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[PATCH v4 1/1] remove toast reloptions
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* [PATCH v4 1/1] remove toast reloptions
@ 2026-04-07 20:30  Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Nathan Bossart @ 2026-04-07 20:30 UTC (permalink / raw)

---
 doc/src/sgml/ref/create_table.sgml            | 51 ++++++-------
 src/backend/access/common/reloptions.c        | 49 +++++-------
 src/backend/catalog/toasting.c                | 31 ++++----
 src/backend/commands/createas.c               | 13 +---
 src/backend/commands/repack.c                 | 15 +---
 src/backend/commands/tablecmds.c              | 19 +----
 src/backend/commands/vacuum.c                 | 14 +---
 src/backend/postmaster/autovacuum.c           | 48 +++++-------
 src/backend/tcop/utility.c                    | 19 +----
 src/bin/pg_upgrade/check.c                    | 75 +++++++++++++++++++
 src/include/access/reloptions.h               | 24 +++---
 src/include/catalog/toasting.h                |  6 +-
 .../injection_points/expected/vacuum.out      | 24 +++---
 .../modules/injection_points/sql/vacuum.sql   | 20 ++---
 src/test/regress/expected/alter_table.out     |  9 ---
 src/test/regress/expected/reloptions.out      | 56 ++------------
 src/test/regress/expected/vacuum.out          |  8 --
 src/test/regress/sql/alter_table.sql          |  4 -
 src/test/regress/sql/reloptions.sql           | 32 +-------
 src/test/regress/sql/vacuum.sql               |  8 --
 20 files changed, 199 insertions(+), 326 deletions(-)

diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index e342585c7f0..b8d2a657d10 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1589,14 +1589,10 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
     Storage parameters for
     indexes are documented in <xref linkend="sql-createindex"/>.
     The storage parameters currently
-    available for tables are listed below.  For many of these parameters, as
-    shown, there is an additional parameter with the same name prefixed with
-    <literal>toast.</literal>, which controls the behavior of the
+    available for tables are listed below.  Unless otherwise noted, a table's
+    parameter value also controls the behavior of the
     table's secondary <acronym>TOAST</acronym> table, if any
     (see <xref linkend="storage-toast"/> for more information about TOAST).
-    If a table parameter value is set and the
-    equivalent <literal>toast.</literal> parameter is not, the TOAST table
-    will use the table's parameter value.
     Specifying these parameters for partitioned tables is not supported,
     but you may specify them for individual leaf partitions.
    </para>
@@ -1622,7 +1618,8 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       updates</link> more likely.
       For a table whose entries are never updated, complete packing is the
       best choice, but in heavily updated tables smaller fillfactors are
-      appropriate.  This parameter cannot be set for TOAST tables.
+      appropriate.  This parameter does not affect the table's secondary TOAST
+      table.
      </para>
     </listitem>
    </varlistentry>
@@ -1648,7 +1645,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       Note that the default setting is often close to optimal, and
       it is possible that setting this parameter could have negative
       effects in some cases.
-      This parameter cannot be set for TOAST tables.
+      This parameter does not affect the table's secondary TOAST table.
      </para>
     </listitem>
    </varlistentry>
@@ -1671,7 +1668,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-enabled" xreflabel="autovacuum_enabled">
-    <term><literal>autovacuum_enabled</literal>, <literal>toast.autovacuum_enabled</literal> (<type>boolean</type>)
+    <term><literal>autovacuum_enabled</literal> (<type>boolean</type>)
     <indexterm>
      <primary><varname>autovacuum_enabled</varname> storage parameter</primary>
     </indexterm>
@@ -1696,7 +1693,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-vacuum-index-cleanup" xreflabel="vacuum_index_cleanup">
-    <term><literal>vacuum_index_cleanup</literal>, <literal>toast.vacuum_index_cleanup</literal> (<type>enum</type>)
+    <term><literal>vacuum_index_cleanup</literal> (<type>enum</type>)
     <indexterm>
      <primary><varname>vacuum_index_cleanup</varname> storage parameter</primary>
     </indexterm>
@@ -1722,7 +1719,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-vacuum-truncate" xreflabel="vacuum_truncate">
-    <term><literal>vacuum_truncate</literal>, <literal>toast.vacuum_truncate</literal> (<type>boolean</type>)
+    <term><literal>vacuum_truncate</literal> (<type>boolean</type>)
     <indexterm>
      <primary><varname>vacuum_truncate</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1755,7 +1752,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-threshold" xreflabel="autovacuum_vacuum_threshold">
-    <term><literal>autovacuum_vacuum_threshold</literal>, <literal>toast.autovacuum_vacuum_threshold</literal> (<type>integer</type>)
+    <term><literal>autovacuum_vacuum_threshold</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_threshold</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1770,7 +1767,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-max-threshold" xreflabel="autovacuum_vacuum_max_threshold">
-    <term><literal>autovacuum_vacuum_max_threshold</literal>, <literal>toast.autovacuum_vacuum_max_threshold</literal> (<type>integer</type>)
+    <term><literal>autovacuum_vacuum_max_threshold</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_max_threshold</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1785,7 +1782,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
   </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-scale-factor" xreflabel="autovacuum_vacuum_scale_factor">
-    <term><literal>autovacuum_vacuum_scale_factor</literal>, <literal>toast.autovacuum_vacuum_scale_factor</literal> (<type>floating point</type>)
+    <term><literal>autovacuum_vacuum_scale_factor</literal> (<type>floating point</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_scale_factor</varname> </primary>
      <secondary>storage parameter</secondary>
@@ -1800,7 +1797,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-insert-threshold" xreflabel="autovacuum_vacuum_insert_threshold">
-    <term><literal>autovacuum_vacuum_insert_threshold</literal>, <literal>toast.autovacuum_vacuum_insert_threshold</literal> (<type>integer</type>)
+    <term><literal>autovacuum_vacuum_insert_threshold</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_insert_threshold</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1815,7 +1812,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-insert-scale-factor" xreflabel="autovacuum_vacuum_insert_scale_factor">
-    <term><literal>autovacuum_vacuum_insert_scale_factor</literal>, <literal>toast.autovacuum_vacuum_insert_scale_factor</literal> (<type>floating point</type>)
+    <term><literal>autovacuum_vacuum_insert_scale_factor</literal> (<type>floating point</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_insert_scale_factor</varname> </primary>
      <secondary>storage parameter</secondary>
@@ -1860,7 +1857,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-cost-delay" xreflabel="autovacuum_vacuum_cost_delay">
-    <term><literal>autovacuum_vacuum_cost_delay</literal>, <literal>toast.autovacuum_vacuum_cost_delay</literal> (<type>floating point</type>)
+    <term><literal>autovacuum_vacuum_cost_delay</literal> (<type>floating point</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_cost_delay</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1875,7 +1872,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-vacuum-cost-limit" xreflabel="autovacuum_vacuum_cost_limit">
-    <term><literal>autovacuum_vacuum_cost_limit</literal>, <literal>toast.autovacuum_vacuum_cost_limit</literal> (<type>integer</type>)
+    <term><literal>autovacuum_vacuum_cost_limit</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_vacuum_cost_limit</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1890,7 +1887,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-freeze-min-age" xreflabel="autovacuum_freeze_min_age">
-    <term><literal>autovacuum_freeze_min_age</literal>, <literal>toast.autovacuum_freeze_min_age</literal> (<type>integer</type>)
+    <term><literal>autovacuum_freeze_min_age</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_freeze_min_age</varname> storage parameter</primary>
     </indexterm>
@@ -1907,7 +1904,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-freeze-max-age" xreflabel="autovacuum_freeze_max_age">
-    <term><literal>autovacuum_freeze_max_age</literal>, <literal>toast.autovacuum_freeze_max_age</literal> (<type>integer</type>)
+    <term><literal>autovacuum_freeze_max_age</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_freeze_max_age</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1924,7 +1921,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-freeze-table-age" xreflabel="autovacuum_freeze_table_age">
-    <term><literal>autovacuum_freeze_table_age</literal>, <literal>toast.autovacuum_freeze_table_age</literal> (<type>integer</type>)
+    <term><literal>autovacuum_freeze_table_age</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_freeze_table_age</varname> storage parameter</primary>
     </indexterm>
@@ -1938,7 +1935,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-multixact-freeze-min-age" xreflabel="autovacuum_multixact_freeze_min_age">
-    <term><literal>autovacuum_multixact_freeze_min_age</literal>, <literal>toast.autovacuum_multixact_freeze_min_age</literal> (<type>integer</type>)
+    <term><literal>autovacuum_multixact_freeze_min_age</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_multixact_freeze_min_age</varname> storage parameter</primary>
     </indexterm>
@@ -1956,7 +1953,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-multixact-freeze-max-age" xreflabel="autovacuum_multixact_freeze_max_age">
-    <term><literal>autovacuum_multixact_freeze_max_age</literal>, <literal>toast.autovacuum_multixact_freeze_max_age</literal> (<type>integer</type>)
+    <term><literal>autovacuum_multixact_freeze_max_age</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_multixact_freeze_max_age</varname></primary>
      <secondary>storage parameter</secondary>
@@ -1975,7 +1972,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-autovacuum-multixact-freeze-table-age" xreflabel="autovacuum_multixact_freeze_table_age">
-    <term><literal>autovacuum_multixact_freeze_table_age</literal>, <literal>toast.autovacuum_multixact_freeze_table_age</literal> (<type>integer</type>)
+    <term><literal>autovacuum_multixact_freeze_table_age</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>autovacuum_multixact_freeze_table_age</varname> storage parameter</primary>
     </indexterm>
@@ -1989,7 +1986,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-log-autovacuum-min-duration" xreflabel="log_autovacuum_min_duration">
-    <term><literal>log_autovacuum_min_duration</literal>, <literal>toast.log_autovacuum_min_duration</literal> (<type>integer</type>)
+    <term><literal>log_autovacuum_min_duration</literal> (<type>integer</type>)
     <indexterm>
      <primary><varname>log_autovacuum_min_duration</varname></primary>
      <secondary>storage parameter</secondary>
@@ -2019,7 +2016,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
    </varlistentry>
 
    <varlistentry id="reloption-vacuum-max-eager-freeze-failure-rate" xreflabel="vacuum_max_eager_freeze_failure_rate">
-    <term><literal>vacuum_max_eager_freeze_failure_rate</literal>, <literal>toast.vacuum_max_eager_freeze_failure_rate</literal> (<type>floating point</type>)
+    <term><literal>vacuum_max_eager_freeze_failure_rate</literal> (<type>floating point</type>)
     <indexterm>
      <primary><varname>vacuum_max_eager_freeze_failure_rate</varname></primary>
      <secondary>storage parameter</secondary>
@@ -2044,7 +2041,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       Declare the table as an additional catalog table for purposes of
       logical replication. See
       <xref linkend="logicaldecoding-capabilities"/> for details.
-      This parameter cannot be set for TOAST tables.
+      This parameter does not affect the table's secondary TOAST table.
      </para>
     </listitem>
    </varlistentry>
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 3e832c3797e..50d9805f3d8 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -111,7 +111,7 @@ static relopt_bool boolRelOpts[] =
 		{
 			"autovacuum_enabled",
 			"Enables autovacuum in this relation",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		true
@@ -172,7 +172,7 @@ static relopt_ternary ternaryRelOpts[] =
 		{
 			"vacuum_truncate",
 			"Enables vacuum to truncate empty pages at the end of this table",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		}
 	},
@@ -249,7 +249,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_vacuum_threshold",
 			"Minimum number of tuple updates or deletes prior to vacuum",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0, INT_MAX
@@ -258,7 +258,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_vacuum_max_threshold",
 			"Maximum number of tuple updates or deletes prior to vacuum",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-2, -1, INT_MAX
@@ -267,7 +267,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_vacuum_insert_threshold",
 			"Minimum number of tuple inserts prior to vacuum, or -1 to disable insert vacuums",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-2, -1, INT_MAX
@@ -285,7 +285,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_vacuum_cost_limit",
 			"Vacuum cost amount available before napping, for autovacuum",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 1, 10000
@@ -294,7 +294,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_freeze_min_age",
 			"Minimum age at which VACUUM should freeze a table row, for autovacuum",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0, 1000000000
@@ -303,7 +303,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_multixact_freeze_min_age",
 			"Minimum multixact age at which VACUUM should freeze a row multixact's, for autovacuum",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0, 1000000000
@@ -312,7 +312,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_freeze_max_age",
 			"Age at which to autovacuum a table to prevent transaction ID wraparound",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 100000, 2000000000
@@ -321,7 +321,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_multixact_freeze_max_age",
 			"Multixact age at which to autovacuum a table to prevent multixact wraparound",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 10000, 2000000000
@@ -330,7 +330,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_freeze_table_age",
 			"Age at which VACUUM should perform a full table sweep to freeze row versions",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		}, -1, 0, 2000000000
 	},
@@ -338,7 +338,7 @@ static relopt_int intRelOpts[] =
 		{
 			"autovacuum_multixact_freeze_table_age",
 			"Age of multixact at which VACUUM should perform a full table sweep to freeze row versions",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		}, -1, 0, 2000000000
 	},
@@ -346,7 +346,7 @@ static relopt_int intRelOpts[] =
 		{
 			"log_autovacuum_min_duration",
 			"Sets the minimum execution time above which vacuum actions by autovacuum will be logged",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, -1, INT_MAX
@@ -424,7 +424,7 @@ static relopt_real realRelOpts[] =
 		{
 			"autovacuum_vacuum_cost_delay",
 			"Vacuum cost delay in milliseconds, for autovacuum",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0.0, 100.0
@@ -433,7 +433,7 @@ static relopt_real realRelOpts[] =
 		{
 			"autovacuum_vacuum_scale_factor",
 			"Number of tuple updates or deletes prior to vacuum as a fraction of reltuples",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0.0, 100.0
@@ -442,7 +442,7 @@ static relopt_real realRelOpts[] =
 		{
 			"autovacuum_vacuum_insert_scale_factor",
 			"Number of tuple inserts prior to vacuum as a fraction of reltuples",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0.0, 100.0
@@ -460,7 +460,7 @@ static relopt_real realRelOpts[] =
 		{
 			"vacuum_max_eager_freeze_failure_rate",
 			"Fraction of pages in a relation vacuum can scan and fail to freeze before disabling eager scanning.",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		-1, 0.0, 1.0
@@ -554,7 +554,7 @@ static relopt_enum enumRelOpts[] =
 		{
 			"vacuum_index_cleanup",
 			"Controls index vacuuming and index cleanup",
-			RELOPT_KIND_HEAP | RELOPT_KIND_TOAST,
+			RELOPT_KIND_HEAP,
 			ShareUpdateExclusiveLock
 		},
 		StdRdOptIndexCleanupValues,
@@ -2163,21 +2163,8 @@ view_reloptions(Datum reloptions, bool validate)
 bytea *
 heap_reloptions(char relkind, Datum reloptions, bool validate)
 {
-	StdRdOptions *rdopts;
-
 	switch (relkind)
 	{
-		case RELKIND_TOASTVALUE:
-			rdopts = (StdRdOptions *)
-				default_reloptions(reloptions, validate, RELOPT_KIND_TOAST);
-			if (rdopts != NULL)
-			{
-				/* adjust default-only parameters for TOAST relations */
-				rdopts->fillfactor = 100;
-				rdopts->autovacuum.analyze_threshold = -1;
-				rdopts->autovacuum.analyze_scale_factor = -1;
-			}
-			return (bytea *) rdopts;
 		case RELKIND_RELATION:
 		case RELKIND_MATVIEW:
 			return default_reloptions(reloptions, validate, RELOPT_KIND_HEAP);
diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c
index 4aa52a4bd25..9f1f822702c 100644
--- a/src/backend/catalog/toasting.c
+++ b/src/backend/catalog/toasting.c
@@ -34,11 +34,11 @@
 #include "utils/rel.h"
 #include "utils/syscache.h"
 
-static void CheckAndCreateToastTable(Oid relOid, Datum reloptions,
+static void CheckAndCreateToastTable(Oid relOid,
 									 LOCKMODE lockmode, bool check,
 									 Oid OIDOldToast);
 static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
-							   Datum reloptions, LOCKMODE lockmode, bool check,
+							   LOCKMODE lockmode, bool check,
 							   Oid OIDOldToast);
 static bool needs_toast_table(Relation rel);
 
@@ -48,35 +48,30 @@ static bool needs_toast_table(Relation rel);
  *		If the table needs a toast table, and doesn't already have one,
  *		then create a toast table for it.
  *
- * reloptions for the toast table can be passed, too.  Pass (Datum) 0
- * for default reloptions.
- *
  * We expect the caller to have verified that the relation is a table and have
  * already done any necessary permission checks.  Callers expect this function
  * to end with CommandCounterIncrement if it makes any changes.
  */
 void
-AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
+AlterTableCreateToastTable(Oid relOid, LOCKMODE lockmode)
 {
-	CheckAndCreateToastTable(relOid, reloptions, lockmode, true, InvalidOid);
+	CheckAndCreateToastTable(relOid, lockmode, true, InvalidOid);
 }
 
 void
-NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
-						Oid OIDOldToast)
+NewHeapCreateToastTable(Oid relOid, LOCKMODE lockmode, Oid OIDOldToast)
 {
-	CheckAndCreateToastTable(relOid, reloptions, lockmode, false, OIDOldToast);
+	CheckAndCreateToastTable(relOid, lockmode, false, OIDOldToast);
 }
 
 void
-NewRelationCreateToastTable(Oid relOid, Datum reloptions)
+NewRelationCreateToastTable(Oid relOid)
 {
-	CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false,
-							 InvalidOid);
+	CheckAndCreateToastTable(relOid, AccessExclusiveLock, false, InvalidOid);
 }
 
 static void
-CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
+CheckAndCreateToastTable(Oid relOid, LOCKMODE lockmode,
 						 bool check, Oid OIDOldToast)
 {
 	Relation	rel;
@@ -84,7 +79,7 @@ CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
 	rel = table_open(relOid, lockmode);
 
 	/* create_toast_table does all the work */
-	(void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode,
+	(void) create_toast_table(rel, InvalidOid, InvalidOid, lockmode,
 							  check, OIDOldToast);
 
 	table_close(rel, NoLock);
@@ -108,7 +103,7 @@ BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
 			 relName);
 
 	/* create_toast_table does all the work */
-	if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0,
+	if (!create_toast_table(rel, toastOid, toastIndexOid,
 							AccessExclusiveLock, false, InvalidOid))
 		elog(ERROR, "\"%s\" does not require a toast table",
 			 relName);
@@ -126,7 +121,7 @@ BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
  */
 static bool
 create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
-				   Datum reloptions, LOCKMODE lockmode, bool check,
+				   LOCKMODE lockmode, bool check,
 				   Oid OIDOldToast)
 {
 	Oid			relOid = RelationGetRelid(rel);
@@ -266,7 +261,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
 										   shared_relation,
 										   mapped_relation,
 										   ONCOMMIT_NOOP,
-										   reloptions,
+										   (Datum) 0,
 										   false,
 										   true,
 										   true,
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index 6dbb831ca89..188e167999b 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -84,8 +84,6 @@ create_ctas_internal(List *attrList, IntoClause *into)
 	CreateStmt *create = makeNode(CreateStmt);
 	bool		is_matview;
 	char		relkind;
-	Datum		toast_options;
-	const char *const validnsps[] = HEAP_RELOPT_NAMESPACES;
 	ObjectAddress intoRelationAddr;
 
 	/* This code supports both CREATE TABLE AS and CREATE MATERIALIZED VIEW */
@@ -120,16 +118,7 @@ create_ctas_internal(List *attrList, IntoClause *into)
 	 */
 	CommandCounterIncrement();
 
-	/* parse and validate reloptions for the toast table */
-	toast_options = transformRelOptions((Datum) 0,
-										create->options,
-										"toast",
-										validnsps,
-										true, false);
-
-	(void) heap_reloptions(RELKIND_TOASTVALUE, toast_options, true);
-
-	NewRelationCreateToastTable(intoRelationAddr.objectId, toast_options);
+	NewRelationCreateToastTable(intoRelationAddr.objectId);
 
 	/* Create the "view" part of a materialized view. */
 	if (is_matview)
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 9a199dd9bfb..3b80d331815 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -1201,20 +1201,7 @@ make_new_heap(Oid OIDOldHeap, Oid NewTableSpace, Oid NewAccessMethod,
 	 */
 	toastid = OldHeap->rd_rel->reltoastrelid;
 	if (OidIsValid(toastid))
-	{
-		/* keep the existing toast table's reloptions, if any */
-		tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid));
-		if (!HeapTupleIsValid(tuple))
-			elog(ERROR, "cache lookup failed for relation %u", toastid);
-		reloptions = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
-									 &isNull);
-		if (isNull)
-			reloptions = (Datum) 0;
-
-		NewHeapCreateToastTable(OIDNewHeap, reloptions, lockmode, toastid);
-
-		ReleaseSysCache(tuple);
-	}
+		NewHeapCreateToastTable(OIDNewHeap, lockmode, toastid);
 
 	table_close(OldHeap, NoLock);
 
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index d8d7969bf30..a254509cbb5 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -827,7 +827,6 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	ListCell   *listptr;
 	AttrNumber	attnum;
 	bool		partitioned;
-	const char *const validnsps[] = HEAP_RELOPT_NAMESPACES;
 	Oid			ofTypeId;
 	ObjectAddress address;
 	LOCKMODE	parentLockmode;
@@ -976,7 +975,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
 	/*
 	 * Parse and validate reloptions, if any.
 	 */
-	reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
+	reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, NULL,
 									 true, false);
 
 	switch (relkind)
@@ -5433,7 +5432,7 @@ ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode,
 			  tab->relkind == RELKIND_PARTITIONED_TABLE) &&
 			 tab->partition_constraint == NULL) ||
 			tab->relkind == RELKIND_MATVIEW)
-			AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode);
+			AlterTableCreateToastTable(tab->relid, lockmode);
 	}
 }
 
@@ -16927,7 +16926,6 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
 	Datum		repl_val[Natts_pg_class];
 	bool		repl_null[Natts_pg_class];
 	bool		repl_repl[Natts_pg_class];
-	const char *const validnsps[] = HEAP_RELOPT_NAMESPACES;
 
 	if (defList == NIL && operation != AT_ReplaceRelOptions)
 		return;					/* nothing to do */
@@ -16960,7 +16958,7 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
 	}
 
 	/* Generate new proposed reloptions (text array) */
-	newOptions = transformRelOptions(datum, defList, NULL, validnsps, false,
+	newOptions = transformRelOptions(datum, defList, NULL, NULL, false,
 									 operation == AT_ResetRelOptions);
 
 	/* Validate */
@@ -17083,20 +17081,11 @@ ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
 				datum = (Datum) 0;
 		}
 
-		newOptions = transformRelOptions(datum, defList, "toast", validnsps,
-										 false, operation == AT_ResetRelOptions);
-
-		(void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true);
-
 		memset(repl_val, 0, sizeof(repl_val));
 		memset(repl_null, false, sizeof(repl_null));
 		memset(repl_repl, false, sizeof(repl_repl));
 
-		if (newOptions != (Datum) 0)
-			repl_val[Anum_pg_class_reloptions - 1] = newOptions;
-		else
-			repl_null[Anum_pg_class_reloptions - 1] = true;
-
+		repl_null[Anum_pg_class_reloptions - 1] = true;
 		repl_repl[Anum_pg_class_reloptions - 1] = true;
 
 		newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..2b44afdbf25 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -2020,13 +2020,6 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	Oid			save_userid;
 	int			save_sec_context;
 	int			save_nestlevel;
-	VacuumParams toast_vacuum_params;
-
-	/*
-	 * This function scribbles on the parameters, so make a copy early to
-	 * avoid affecting the TOAST table (if we do end up recursing to it).
-	 */
-	memcpy(&toast_vacuum_params, &params, sizeof(VacuumParams));
 
 	/* Begin a transaction for vacuuming this relation */
 	StartTransactionCommand();
@@ -2341,11 +2334,10 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		 * relation.  NB: This is only safe to do because we hold a session
 		 * lock on the main relation that prevents concurrent deletion.
 		 */
-		toast_vacuum_params.options |= VACOPT_PROCESS_MAIN;
-		toast_vacuum_params.toast_parent = relid;
+		params.options |= VACOPT_PROCESS_MAIN;
+		params.toast_parent = relid;
 
-		vacuum_rel(toast_relid, NULL, toast_vacuum_params, bstrategy,
-				   isTopLevel);
+		vacuum_rel(toast_relid, NULL, params, bstrategy, isTopLevel);
 	}
 
 	/*
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index a5a8db2ff88..c0e7cbf2cb8 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2139,8 +2139,9 @@ do_autovacuum(void)
 	{
 		Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
 		Oid			relid;
-		AutoVacOpts *relopts;
-		bool		free_relopts = false;
+		av_relation *hentry;
+		bool		found;
+		AutoVacOpts *relopts = NULL;
 		bool		dovacuum;
 		bool		doanalyze;
 		bool		wraparound;
@@ -2154,22 +2155,10 @@ do_autovacuum(void)
 
 		relid = classForm->oid;
 
-		/*
-		 * fetch reloptions -- if this toast table does not have them, try the
-		 * main rel
-		 */
-		relopts = extract_autovac_opts(tuple, pg_class_desc);
-		if (relopts)
-			free_relopts = true;
-		else
-		{
-			av_relation *hentry;
-			bool		found;
-
-			hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
-			if (found && hentry->ar_hasrelopts)
-				relopts = &hentry->ar_reloptions;
-		}
+		/* Use reloptions from main rel. */
+		hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
+		if (found && hentry->ar_hasrelopts)
+			relopts = &hentry->ar_reloptions;
 
 		relation_needs_vacanalyze(relid, relopts, classForm,
 								  effective_multixact_freeze_max_age,
@@ -2186,10 +2175,6 @@ do_autovacuum(void)
 			table->score = scores.max;
 			tables_to_process = lappend(tables_to_process, table);
 		}
-
-		/* Release stuff to avoid leakage */
-		if (free_relopts)
-			pfree(relopts);
 	}
 
 	table_endscan(relScan);
@@ -2826,7 +2811,7 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 	bool		doanalyze;
 	autovac_table *tab = NULL;
 	bool		wraparound;
-	AutoVacOpts *avopts;
+	AutoVacOpts *avopts = NULL;
 	bool		free_avopts = false;
 	AutoVacuumScores scores;
 
@@ -2838,13 +2823,15 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 
 	/*
 	 * Get the applicable reloptions.  If it is a TOAST table, try to get the
-	 * main table reloptions if the toast table itself doesn't have.
+	 * main table reloptions.
 	 */
-	avopts = extract_autovac_opts(classTup, pg_class_desc);
-	if (avopts)
-		free_avopts = true;
-	else if (classForm->relkind == RELKIND_TOASTVALUE &&
-			 table_toast_map != NULL)
+	if (classForm->relkind != RELKIND_TOASTVALUE)
+	{
+		avopts = extract_autovac_opts(classTup, pg_class_desc);
+		if (avopts)
+			free_avopts = true;
+	}
+	else if (table_toast_map)
 	{
 		av_relation *hentry;
 		bool		found;
@@ -3127,8 +3114,7 @@ relation_needs_vacanalyze(Oid relid,
 
 	/*
 	 * Determine vacuum/analyze equation parameters.  We have two possible
-	 * sources: the passed reloptions (which could be a main table or a toast
-	 * table), or the autovacuum GUC variables.
+	 * sources: the passed reloptions or the autovacuum GUC variables.
 	 */
 
 	/* -1 in autovac setting means use plain vacuum_scale_factor */
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 73a56f1df1d..d089e02c216 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1159,8 +1159,6 @@ ProcessUtilitySlow(ParseState *pstate,
 						if (IsA(stmt, CreateStmt))
 						{
 							CreateStmt *cstmt = (CreateStmt *) stmt;
-							Datum		toast_options;
-							const char *const validnsps[] = HEAP_RELOPT_NAMESPACES;
 
 							/* Remember transformed RangeVar for LIKE */
 							table_rv = cstmt->relation;
@@ -1180,22 +1178,7 @@ ProcessUtilitySlow(ParseState *pstate,
 							 */
 							CommandCounterIncrement();
 
-							/*
-							 * parse and validate reloptions for the toast
-							 * table
-							 */
-							toast_options = transformRelOptions((Datum) 0,
-																cstmt->options,
-																"toast",
-																validnsps,
-																true,
-																false);
-							(void) heap_reloptions(RELKIND_TOASTVALUE,
-												   toast_options,
-												   true);
-
-							NewRelationCreateToastTable(address.objectId,
-														toast_options);
+							NewRelationCreateToastTable(address.objectId);
 						}
 						else if (IsA(stmt, CreateForeignTableStmt))
 						{
diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 5a7afe62eab..18d49a6fc17 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -37,6 +37,7 @@ static void check_new_cluster_subscription_configuration(void);
 static void check_old_cluster_for_valid_slots(void);
 static void check_old_cluster_subscription_state(void);
 static void check_old_cluster_global_names(ClusterInfo *cluster);
+static void check_for_toast_reloptions(ClusterInfo *cluster);
 
 /*
  * DataTypesUsageChecks - definitions of data type checks for the old cluster
@@ -634,6 +635,9 @@ check_and_dump_old_cluster(void)
 	check_for_prepared_transactions(&old_cluster);
 	check_for_isn_and_int8_passing_mismatch(&old_cluster);
 
+	if (GET_MAJOR_VERSION(old_cluster.major_version) < 2000)
+		check_for_toast_reloptions(&old_cluster);
+
 	if (GET_MAJOR_VERSION(old_cluster.major_version) >= 1700)
 	{
 		/*
@@ -2644,3 +2648,74 @@ check_old_cluster_global_names(ClusterInfo *cluster)
 	else
 		check_ok();
 }
+
+/*
+ * Callback function for processing results of query for
+ * check_for_toast_reloptions()'s UpgradeTask.  If the query returned any rows
+ * (i.e., the check failed), write the details to the report file.
+ */
+static void
+process_toast_relopts_check(DbInfo *dbinfo, PGresult *res, void *arg)
+{
+	UpgradeTaskReport *report = (UpgradeTaskReport *) arg;
+	int			ntups = PQntuples(res);
+	int			i_nspname = PQfnumber(res, "nspname");
+	int			i_relname = PQfnumber(res, "relname");
+
+	if (ntups == 0)
+		return;
+
+	if (report->file == NULL &&
+		(report->file = fopen_priv(report->path, "w")) == NULL)
+		pg_fatal("could not open file \"%s\": %m", report->path);
+
+	fprintf(report->file, "In database: %s\n", dbinfo->db_name);
+
+	for (int rowno = 0; rowno < ntups; rowno++)
+		fprintf(report->file, "  %s.%s\n",
+				PQgetvalue(res, rowno, i_nspname),
+				PQgetvalue(res, rowno, i_relname));
+}
+
+/*
+ * Verify that no storage parameters (a.k.a. reloptions) are defined for TOAST
+ * tables.
+ */
+static void
+check_for_toast_reloptions(ClusterInfo *cluster)
+{
+	UpgradeTaskReport report;
+	UpgradeTask *task = upgrade_task_create();
+	const char *query = "SELECT n.nspname, c.relname "
+		"FROM  pg_catalog.pg_class c, "
+		"      pg_catalog.pg_class tc, "
+		"      pg_catalog.pg_namespace n "
+		"WHERE c.reltoastrelid = tc.oid AND "
+		"      c.relnamespace = n.oid AND "
+		"      tc.reloptions IS NOT NULL";
+
+	prep_status("Check for tables with TOAST storage parameters");
+
+	report.file = NULL;
+	snprintf(report.path, sizeof(report.path), "%s/%s",
+			 log_opts.basedir,
+			 "tables_with_toast_storage_parameters.txt");
+
+	upgrade_task_add_step(task, query, process_toast_relopts_check,
+						  true, &report);
+	upgrade_task_run(task, cluster);
+	upgrade_task_free(task);
+
+	if (report.file)
+	{
+		fclose(report.file);
+		pg_log(PG_REPORT, "fatal");
+		pg_fatal("Your installation contains tables with TOAST storage parameters set, which is\n"
+				 "not supported anymore.  Consider remove the TOAST storage parameters using\n"
+				 "    ALTER TABLE ... RESET ( ... );\n"
+				 "A list of tables with the problem is in the file:\n"
+				 "    %s", report.path);
+	}
+	else
+		check_ok();
+}
diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h
index e8cb7f7a627..4415c1ca9b5 100644
--- a/src/include/access/reloptions.h
+++ b/src/include/access/reloptions.h
@@ -40,26 +40,22 @@ typedef enum relopt_kind
 {
 	RELOPT_KIND_LOCAL = 0,
 	RELOPT_KIND_HEAP = (1 << 0),
-	RELOPT_KIND_TOAST = (1 << 1),
-	RELOPT_KIND_BTREE = (1 << 2),
-	RELOPT_KIND_HASH = (1 << 3),
-	RELOPT_KIND_GIN = (1 << 4),
-	RELOPT_KIND_GIST = (1 << 5),
-	RELOPT_KIND_ATTRIBUTE = (1 << 6),
-	RELOPT_KIND_TABLESPACE = (1 << 7),
-	RELOPT_KIND_SPGIST = (1 << 8),
-	RELOPT_KIND_VIEW = (1 << 9),
-	RELOPT_KIND_BRIN = (1 << 10),
-	RELOPT_KIND_PARTITIONED = (1 << 11),
+	RELOPT_KIND_BTREE = (1 << 1),
+	RELOPT_KIND_HASH = (1 << 2),
+	RELOPT_KIND_GIN = (1 << 3),
+	RELOPT_KIND_GIST = (1 << 4),
+	RELOPT_KIND_ATTRIBUTE = (1 << 5),
+	RELOPT_KIND_TABLESPACE = (1 << 6),
+	RELOPT_KIND_SPGIST = (1 << 7),
+	RELOPT_KIND_VIEW = (1 << 8),
+	RELOPT_KIND_BRIN = (1 << 9),
+	RELOPT_KIND_PARTITIONED = (1 << 10),
 	/* if you add a new kind, make sure you update "last_default" too */
 	RELOPT_KIND_LAST_DEFAULT = RELOPT_KIND_PARTITIONED,
 	/* some compilers treat enums as signed ints, so we can't use 1 << 31 */
 	RELOPT_KIND_MAX = (1 << 30)
 } relopt_kind;
 
-/* reloption namespaces allowed for heaps -- currently only TOAST */
-#define HEAP_RELOPT_NAMESPACES { "toast", NULL }
-
 /* generic struct to hold shared data */
 typedef struct relopt_gen
 {
diff --git a/src/include/catalog/toasting.h b/src/include/catalog/toasting.h
index 0bc61a8fee9..13e5a8affcb 100644
--- a/src/include/catalog/toasting.h
+++ b/src/include/catalog/toasting.h
@@ -19,10 +19,10 @@
 /*
  * toasting.c prototypes
  */
-extern void NewRelationCreateToastTable(Oid relOid, Datum reloptions);
-extern void NewHeapCreateToastTable(Oid relOid, Datum reloptions,
+extern void NewRelationCreateToastTable(Oid relOid);
+extern void NewHeapCreateToastTable(Oid relOid,
 									LOCKMODE lockmode, Oid OIDOldToast);
-extern void AlterTableCreateToastTable(Oid relOid, Datum reloptions,
+extern void AlterTableCreateToastTable(Oid relOid,
 									   LOCKMODE lockmode);
 extern void BootstrapToastTable(char *relName,
 								Oid toastOid, Oid toastIndexOid);
diff --git a/src/test/modules/injection_points/expected/vacuum.out b/src/test/modules/injection_points/expected/vacuum.out
index 58df59fa927..dcfa729d05e 100644
--- a/src/test/modules/injection_points/expected/vacuum.out
+++ b/src/test/modules/injection_points/expected/vacuum.out
@@ -43,29 +43,29 @@ SELECT injection_points_attach('vacuum-truncate-enabled', 'notice');
 (1 row)
 
 -- Check state of index_cleanup and truncate in VACUUM.
-CREATE TABLE vac_tab_on_toast_off(i int, j text) WITH
+CREATE TABLE vac_tab_on_toast(i int, j text) WITH
   (autovacuum_enabled=false,
-   vacuum_index_cleanup=true, toast.vacuum_index_cleanup=false,
-   vacuum_truncate=true, toast.vacuum_truncate=false);
-CREATE TABLE vac_tab_off_toast_on(i int, j text) WITH
+   vacuum_index_cleanup=true,
+   vacuum_truncate=true);
+CREATE TABLE vac_tab_off_toast(i int, j text) WITH
   (autovacuum_enabled=false,
-   vacuum_index_cleanup=false, toast.vacuum_index_cleanup=true,
-   vacuum_truncate=false, toast.vacuum_truncate=true);
+   vacuum_index_cleanup=false,
+   vacuum_truncate=false);
 -- Multiple relations should use their options in isolation.
-VACUUM vac_tab_on_toast_off, vac_tab_off_toast_on;
+VACUUM vac_tab_on_toast, vac_tab_off_toast;
+NOTICE:  notice triggered for injection point vacuum-index-cleanup-enabled
+NOTICE:  notice triggered for injection point vacuum-truncate-enabled
 NOTICE:  notice triggered for injection point vacuum-index-cleanup-enabled
 NOTICE:  notice triggered for injection point vacuum-truncate-enabled
 NOTICE:  notice triggered for injection point vacuum-index-cleanup-disabled
 NOTICE:  notice triggered for injection point vacuum-truncate-disabled
 NOTICE:  notice triggered for injection point vacuum-index-cleanup-disabled
 NOTICE:  notice triggered for injection point vacuum-truncate-disabled
-NOTICE:  notice triggered for injection point vacuum-index-cleanup-enabled
-NOTICE:  notice triggered for injection point vacuum-truncate-enabled
 -- Check "auto" case of index_cleanup and "truncate" controlled by
 -- its GUC.
 CREATE TABLE vac_tab_auto(i int, j text) WITH
   (autovacuum_enabled=false,
-   vacuum_index_cleanup=auto, toast.vacuum_index_cleanup=auto);
+   vacuum_index_cleanup=auto);
 SET vacuum_truncate = false;
 VACUUM vac_tab_auto;
 NOTICE:  notice triggered for injection point vacuum-index-cleanup-auto
@@ -80,8 +80,8 @@ NOTICE:  notice triggered for injection point vacuum-index-cleanup-auto
 NOTICE:  notice triggered for injection point vacuum-truncate-enabled
 RESET vacuum_truncate;
 DROP TABLE vac_tab_auto;
-DROP TABLE vac_tab_on_toast_off;
-DROP TABLE vac_tab_off_toast_on;
+DROP TABLE vac_tab_on_toast;
+DROP TABLE vac_tab_off_toast;
 -- Cleanup
 SELECT injection_points_detach('vacuum-index-cleanup-auto');
  injection_points_detach 
diff --git a/src/test/modules/injection_points/sql/vacuum.sql b/src/test/modules/injection_points/sql/vacuum.sql
index 23760dd0f38..ee7a2e0566e 100644
--- a/src/test/modules/injection_points/sql/vacuum.sql
+++ b/src/test/modules/injection_points/sql/vacuum.sql
@@ -11,22 +11,22 @@ SELECT injection_points_attach('vacuum-truncate-disabled', 'notice');
 SELECT injection_points_attach('vacuum-truncate-enabled', 'notice');
 
 -- Check state of index_cleanup and truncate in VACUUM.
-CREATE TABLE vac_tab_on_toast_off(i int, j text) WITH
+CREATE TABLE vac_tab_on_toast(i int, j text) WITH
   (autovacuum_enabled=false,
-   vacuum_index_cleanup=true, toast.vacuum_index_cleanup=false,
-   vacuum_truncate=true, toast.vacuum_truncate=false);
-CREATE TABLE vac_tab_off_toast_on(i int, j text) WITH
+   vacuum_index_cleanup=true,
+   vacuum_truncate=true);
+CREATE TABLE vac_tab_off_toast(i int, j text) WITH
   (autovacuum_enabled=false,
-   vacuum_index_cleanup=false, toast.vacuum_index_cleanup=true,
-   vacuum_truncate=false, toast.vacuum_truncate=true);
+   vacuum_index_cleanup=false,
+   vacuum_truncate=false);
 -- Multiple relations should use their options in isolation.
-VACUUM vac_tab_on_toast_off, vac_tab_off_toast_on;
+VACUUM vac_tab_on_toast, vac_tab_off_toast;
 
 -- Check "auto" case of index_cleanup and "truncate" controlled by
 -- its GUC.
 CREATE TABLE vac_tab_auto(i int, j text) WITH
   (autovacuum_enabled=false,
-   vacuum_index_cleanup=auto, toast.vacuum_index_cleanup=auto);
+   vacuum_index_cleanup=auto);
 SET vacuum_truncate = false;
 VACUUM vac_tab_auto;
 SET vacuum_truncate = true;
@@ -34,8 +34,8 @@ VACUUM vac_tab_auto;
 RESET vacuum_truncate;
 
 DROP TABLE vac_tab_auto;
-DROP TABLE vac_tab_on_toast_off;
-DROP TABLE vac_tab_off_toast_on;
+DROP TABLE vac_tab_on_toast;
+DROP TABLE vac_tab_off_toast;
 
 -- Cleanup
 SELECT injection_points_detach('vacuum-index-cleanup-auto');
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 6dd22be0e8d..435e6beea0f 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -2860,15 +2860,6 @@ select * from my_locks order by 1;
  pg_toast  | ShareUpdateExclusiveLock
 (2 rows)
 
-commit;
-begin; alter table alterlock set (toast.autovacuum_enabled = off);
-select * from my_locks order by 1;
-  relname  |       max_lockmode       
------------+--------------------------
- alterlock | ShareUpdateExclusiveLock
- pg_toast  | ShareUpdateExclusiveLock
-(2 rows)
-
 commit;
 begin; alter table alterlock set (autovacuum_enabled = off);
 select * from my_locks order by 1;
diff --git a/src/test/regress/expected/reloptions.out b/src/test/regress/expected/reloptions.out
index e3a974f2611..eff5fbece60 100644
--- a/src/test/regress/expected/reloptions.out
+++ b/src/test/regress/expected/reloptions.out
@@ -120,7 +120,6 @@ SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass;
 DROP TABLE reloptions_test;
 CREATE TEMP TABLE reloptions_test(i INT NOT NULL, j text)
 	WITH (vacuum_truncate=false,
-	toast.vacuum_truncate=false,
 	autovacuum_enabled=false);
 SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass;
                     reloptions                    
@@ -142,9 +141,9 @@ SELECT pg_relation_size('reloptions_test') > 0;
 SELECT reloptions FROM pg_class WHERE oid =
 	(SELECT reltoastrelid FROM pg_class
 	WHERE oid = 'reloptions_test'::regclass);
-       reloptions        
--------------------------
- {vacuum_truncate=false}
+ reloptions 
+------------
+ 
 (1 row)
 
 ALTER TABLE reloptions_test RESET (vacuum_truncate);
@@ -165,56 +164,11 @@ SELECT pg_relation_size('reloptions_test') = 0;
  t
 (1 row)
 
--- Test toast.* options
-DROP TABLE reloptions_test;
-CREATE TABLE reloptions_test (s VARCHAR)
-	WITH (toast.autovacuum_vacuum_cost_delay = 23);
-SELECT reltoastrelid as toast_oid
-	FROM pg_class WHERE oid = 'reloptions_test'::regclass \gset
-SELECT reloptions FROM pg_class WHERE oid = :toast_oid;
-            reloptions             
------------------------------------
- {autovacuum_vacuum_cost_delay=23}
-(1 row)
-
-ALTER TABLE reloptions_test SET (toast.autovacuum_vacuum_cost_delay = 24);
-SELECT reloptions FROM pg_class WHERE oid = :toast_oid;
-            reloptions             
------------------------------------
- {autovacuum_vacuum_cost_delay=24}
-(1 row)
-
-ALTER TABLE reloptions_test RESET (toast.autovacuum_vacuum_cost_delay);
-SELECT reloptions FROM pg_class WHERE oid = :toast_oid;
- reloptions 
-------------
- 
-(1 row)
-
--- Fail on non-existent options in toast namespace
-CREATE TABLE reloptions_test2 (i int) WITH (toast.not_existing_option = 42);
-ERROR:  unrecognized parameter "not_existing_option"
--- Mix TOAST & heap
-DROP TABLE reloptions_test;
-CREATE TABLE reloptions_test (s VARCHAR) WITH
-	(toast.autovacuum_vacuum_cost_delay = 23,
-	autovacuum_vacuum_cost_delay = 24, fillfactor = 40);
-SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass;
-                   reloptions                    
--------------------------------------------------
- {autovacuum_vacuum_cost_delay=24,fillfactor=40}
-(1 row)
-
-SELECT reloptions FROM pg_class WHERE oid = (
-	SELECT reltoastrelid FROM pg_class WHERE oid = 'reloptions_test'::regclass);
-            reloptions             
------------------------------------
- {autovacuum_vacuum_cost_delay=23}
-(1 row)
-
 --
 -- CREATE INDEX, ALTER INDEX for btrees
 --
+DROP TABLE reloptions_test;
+CREATE TABLE reloptions_test (s VARCHAR);
 CREATE INDEX reloptions_test_idx ON reloptions_test (s) WITH (fillfactor=30);
 SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test_idx'::regclass;
    reloptions    
diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out
index d4696bc3325..d551ef57d50 100644
--- a/src/test/regress/expected/vacuum.out
+++ b/src/test/regress/expected/vacuum.out
@@ -209,14 +209,6 @@ VACUUM no_index_cleanup;
 INSERT INTO no_index_cleanup(i, t) VALUES (generate_series(31,60),
     repeat('1234567890',269));
 DELETE FROM no_index_cleanup WHERE i < 45;
--- Only toast index is cleaned up.
-ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = off,
-    toast.vacuum_index_cleanup = yes);
-VACUUM no_index_cleanup;
--- Only parent is cleaned up.
-ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = true,
-    toast.vacuum_index_cleanup = false);
-VACUUM no_index_cleanup;
 -- Test some extra relations.
 VACUUM (INDEX_CLEANUP FALSE) vaccluster;
 VACUUM (INDEX_CLEANUP AUTO) vactst; -- index cleanup option is ignored if no indexes
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index f5f13bbd3e7..410465dc022 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -1784,10 +1784,6 @@ begin; alter table alterlock reset (fillfactor);
 select * from my_locks order by 1;
 commit;
 
-begin; alter table alterlock set (toast.autovacuum_enabled = off);
-select * from my_locks order by 1;
-commit;
-
 begin; alter table alterlock set (autovacuum_enabled = off);
 select * from my_locks order by 1;
 commit;
diff --git a/src/test/regress/sql/reloptions.sql b/src/test/regress/sql/reloptions.sql
index 680c8bf8614..0809a2ae0e4 100644
--- a/src/test/regress/sql/reloptions.sql
+++ b/src/test/regress/sql/reloptions.sql
@@ -75,7 +75,6 @@ DROP TABLE reloptions_test;
 
 CREATE TEMP TABLE reloptions_test(i INT NOT NULL, j text)
 	WITH (vacuum_truncate=false,
-	toast.vacuum_truncate=false,
 	autovacuum_enabled=false);
 SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass;
 INSERT INTO reloptions_test VALUES (1, NULL), (NULL, NULL);
@@ -94,39 +93,12 @@ INSERT INTO reloptions_test VALUES (1, NULL), (NULL, NULL);
 VACUUM (FREEZE, DISABLE_PAGE_SKIPPING) reloptions_test;
 SELECT pg_relation_size('reloptions_test') = 0;
 
--- Test toast.* options
-DROP TABLE reloptions_test;
-
-CREATE TABLE reloptions_test (s VARCHAR)
-	WITH (toast.autovacuum_vacuum_cost_delay = 23);
-SELECT reltoastrelid as toast_oid
-	FROM pg_class WHERE oid = 'reloptions_test'::regclass \gset
-SELECT reloptions FROM pg_class WHERE oid = :toast_oid;
-
-ALTER TABLE reloptions_test SET (toast.autovacuum_vacuum_cost_delay = 24);
-SELECT reloptions FROM pg_class WHERE oid = :toast_oid;
-
-ALTER TABLE reloptions_test RESET (toast.autovacuum_vacuum_cost_delay);
-SELECT reloptions FROM pg_class WHERE oid = :toast_oid;
-
--- Fail on non-existent options in toast namespace
-CREATE TABLE reloptions_test2 (i int) WITH (toast.not_existing_option = 42);
-
--- Mix TOAST & heap
-DROP TABLE reloptions_test;
-
-CREATE TABLE reloptions_test (s VARCHAR) WITH
-	(toast.autovacuum_vacuum_cost_delay = 23,
-	autovacuum_vacuum_cost_delay = 24, fillfactor = 40);
-
-SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test'::regclass;
-SELECT reloptions FROM pg_class WHERE oid = (
-	SELECT reltoastrelid FROM pg_class WHERE oid = 'reloptions_test'::regclass);
-
 --
 -- CREATE INDEX, ALTER INDEX for btrees
 --
+DROP TABLE reloptions_test;
 
+CREATE TABLE reloptions_test (s VARCHAR);
 CREATE INDEX reloptions_test_idx ON reloptions_test (s) WITH (fillfactor=30);
 SELECT reloptions FROM pg_class WHERE oid = 'reloptions_test_idx'::regclass;
 
diff --git a/src/test/regress/sql/vacuum.sql b/src/test/regress/sql/vacuum.sql
index 247b8e23b23..37a84fd9145 100644
--- a/src/test/regress/sql/vacuum.sql
+++ b/src/test/regress/sql/vacuum.sql
@@ -175,14 +175,6 @@ VACUUM no_index_cleanup;
 INSERT INTO no_index_cleanup(i, t) VALUES (generate_series(31,60),
     repeat('1234567890',269));
 DELETE FROM no_index_cleanup WHERE i < 45;
--- Only toast index is cleaned up.
-ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = off,
-    toast.vacuum_index_cleanup = yes);
-VACUUM no_index_cleanup;
--- Only parent is cleaned up.
-ALTER TABLE no_index_cleanup SET (vacuum_index_cleanup = true,
-    toast.vacuum_index_cleanup = false);
-VACUUM no_index_cleanup;
 -- Test some extra relations.
 VACUUM (INDEX_CLEANUP FALSE) vaccluster;
 VACUUM (INDEX_CLEANUP AUTO) vactst; -- index cleanup option is ignored if no indexes
-- 
2.50.1 (Apple Git-155)


--g1KZ71ry6DNksXN0--






^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



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* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



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* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 9407c357f27..fa5a53d04ff 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 9ab74c8df0a..2af586669ae 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -689,6 +689,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1376,22 +1378,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1408,9 +1404,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1495,9 +1489,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1524,7 +1516,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1537,8 +1529,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -3926,27 +3918,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4034,11 +4018,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 2debadd86ed..28b34fd4387 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -503,13 +503,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -528,15 +526,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -546,7 +538,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -670,11 +662,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1207,7 +1196,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 38f9ffcd04f..c0f6217caa6 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23245,9 +23245,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23379,18 +23377,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23427,11 +23416,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index a4abb29cf64..8922d713916 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b4d5abbaca7..90234c3f736 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1325,6 +1325,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



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* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



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* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



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* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



^ permalink  raw  reply  [nested|flat] 284+ messages in thread

* [PATCH 5/8] Simplify the way restrictions are imposed on index functions.
@ 2026-07-15 08:37  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 284+ messages in thread

From: Antonin Houska @ 2026-07-15 08:37 UTC (permalink / raw)

Whenever we expect possible execution of index functions, we need to make sure
that they execute with the appropriate privileges. Also, the core should not
see (and use) values of GUC parameters introduced by the index functions.

This patch introduces functions enable_index_build_security() and
disable_index_build_security() which make the security measures less
verbose. It's needed for the upcoming enhancements of REPACK (CONCURRENTLY),
but looks like useful refactoring anyway.
---
 src/backend/access/brin/brin.c   | 32 ++++----------
 src/backend/catalog/index.c      | 72 ++++++++++++++++++--------------
 src/backend/commands/analyze.c   | 21 +++-------
 src/backend/commands/indexcmds.c | 49 +++++++---------------
 src/backend/commands/repack.c    | 24 +++--------
 src/backend/commands/tablecmds.c | 24 +++--------
 src/backend/commands/vacuum.c    | 23 +++-------
 src/include/catalog/index.h      | 10 +++++
 src/tools/pgindent/typedefs.list |  1 +
 9 files changed, 95 insertions(+), 161 deletions(-)

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index bdb30752e09..2359bffa518 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1391,10 +1391,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 	Oid			heapoid;
 	Relation	indexRel;
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	double		numSummarized = 0;
+	IndexBuildSecurity ibsec;
 
 	if (RecoveryInProgress())
 		ereport(ERROR,
@@ -1420,27 +1418,12 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 		heapRel = table_open(heapoid, ShareUpdateExclusiveLock);
 
 		/*
-		 * Autovacuum calls us.  For its benefit, switch to the table owner's
-		 * userid, so that any index functions are run as that user.  Also
-		 * lock down security-restricted operations and arrange to make GUC
-		 * variable changes local to this command.  This is harmless, albeit
-		 * unnecessary, when called from SQL, because we fail shortly if the
-		 * user does not own the index.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 	}
 	else
-	{
 		heapRel = NULL;
-		/* Set these just to suppress "uninitialized variable" warnings */
-		save_userid = InvalidOid;
-		save_sec_context = -1;
-		save_nestlevel = -1;
-	}
 
 	indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
@@ -1453,7 +1436,8 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 						RelationGetRelationName(indexRel))));
 
 	/* User must own the index (comparable to privileges needed for VACUUM) */
-	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid, save_userid))
+	if (heapRel != NULL && !object_ownercheck(RelationRelationId, indexoid,
+											  ibsec.userid))
 		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
 					   RelationGetRelationName(indexRel));
 
@@ -1477,11 +1461,9 @@ brin_summarize_range(PG_FUNCTION_ARGS)
 				 errmsg("index \"%s\" is not valid",
 						RelationGetRelationName(indexRel))));
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
 
 	index_close(indexRel, ShareUpdateExclusiveLock);
 	table_close(heapRel, ShareUpdateExclusiveLock);
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 81bba4beac7..8eabe232d1e 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1504,11 +1504,9 @@ index_concurrently_build(Oid heapRelationId,
 						 Oid indexRelationId)
 {
 	Relation	heapRel;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	Relation	indexRelation;
 	IndexInfo  *indexInfo;
+	IndexBuildSecurity ibsec;
 
 	/* This had better make sure that a snapshot is active */
 	Assert(ActiveSnapshotSet());
@@ -1517,15 +1515,9 @@ index_concurrently_build(Oid heapRelationId,
 	heapRel = table_open(heapRelationId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexRelationId, RowExclusiveLock);
 
@@ -1542,11 +1534,8 @@ index_concurrently_build(Oid heapRelationId,
 	/* Now build the index */
 	index_build(heapRel, indexRelation, indexInfo, false, true, true);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close both the relations, but keep the locks */
 	table_close(heapRel, NoLock);
@@ -3375,9 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	IndexInfo  *indexInfo;
 	IndexVacuumInfo ivinfo;
 	ValidateIndexState state;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	{
 		const int	progress_index[] = {
@@ -3399,15 +3386,9 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	heapRelation = table_open(heapId, ShareUpdateExclusiveLock);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(heapRelation->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(heapRelation->rd_rel->relowner, &ibsec);
 
 	indexRelation = index_open(indexId, RowExclusiveLock);
 
@@ -3486,11 +3467,8 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 		 "validate_index found %.0f heap tuples, %.0f index tuples; inserted %.0f missing tuples",
 		 state.htups, state.itups, state.tups_inserted);
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Close rels, but keep locks */
 	index_close(indexRelation, NoLock);
@@ -4115,6 +4093,36 @@ reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 	return result;
 }
 
+/*
+ * Before building an index, witch to the table owner's userid, so that any
+ * index functions are run as that user. Also lock down security-restricted
+ * operations and arrange to make GUC variable changes local to this command.
+ *
+ * Information needed later by disable_index_build_security() is stored in
+ * *sec.
+ */
+void
+enable_index_build_security(Oid userid, IndexBuildSecurity *sec)
+{
+	GetUserIdAndSecContext(&sec->userid, &sec->sec_context);
+	SetUserIdAndSecContext(userid,
+						   sec->sec_context | SECURITY_RESTRICTED_OPERATION);
+	sec->nestlevel = NewGUCNestLevel();
+	RestrictSearchPath();
+}
+
+/*
+ * Undo what enable_index_build_security() did.
+ */
+void
+disable_index_build_security(IndexBuildSecurity *sec)
+{
+	/* Roll back any GUC changes executed by index functions */
+	AtEOXact_GUC(false, sec->nestlevel);
+
+	/* Restore userid and security context */
+	SetUserIdAndSecContext(sec->userid, sec->sec_context);
+}
 
 /* ----------------------------------------------------------------
  *		System index reindexing support
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index f66e80b757c..dc2ad77ef9a 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -328,14 +328,12 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	PGRUsage	ru0;
 	TimestampTz starttime = 0;
 	MemoryContext caller_context;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	WalUsage	startwalusage = pgWalUsage;
 	BufferUsage startbufferusage = pgBufferUsage;
 	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
+	IndexBuildSecurity ibsec;
 
 	verbose = (params->options & VACOPT_VERBOSE) != 0;
 	instrument = (verbose || (AmAutoVacuumWorkerProcess() &&
@@ -361,15 +359,9 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 	caller_context = MemoryContextSwitchTo(anl_context);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(onerel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(onerel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * When verbose or autovacuum logging is used, initialize a resource usage
@@ -858,11 +850,8 @@ do_analyze_rel(Relation onerel, const VacuumParams *params,
 		}
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* Restore current context and release memory */
 	MemoryContextSwitchTo(caller_context);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 713bb5d10f1..5bc28c94139 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -699,6 +699,8 @@ DefineIndex(ParseState *pstate,
 	 * Switch to the table owner's userid, so that any index functions are run
 	 * as that user.  Also lock down security-restricted operations.  We
 	 * already arranged to make GUC variable changes local to this command.
+	 *
+	 * XXX Use enable_index_build_security()?
 	 */
 	GetUserIdAndSecContext(&root_save_userid, &root_save_sec_context);
 	SetUserIdAndSecContext(rel->rd_rel->relowner,
@@ -1386,22 +1388,16 @@ DefineIndex(ParseState *pstate,
 			{
 				Oid			childRelid = part_oids[i];
 				Relation	childrel;
-				Oid			child_save_userid;
-				int			child_save_sec_context;
-				int			child_save_nestlevel;
 				List	   *childidxs;
 				ListCell   *cell;
 				AttrMap    *attmap;
 				bool		found = false;
+				IndexBuildSecurity child_ibsec;
 
 				childrel = table_open(childRelid, lockmode);
 
-				GetUserIdAndSecContext(&child_save_userid,
-									   &child_save_sec_context);
-				SetUserIdAndSecContext(childrel->rd_rel->relowner,
-									   child_save_sec_context | SECURITY_RESTRICTED_OPERATION);
-				child_save_nestlevel = NewGUCNestLevel();
-				RestrictSearchPath();
+				enable_index_build_security(childrel->rd_rel->relowner,
+											&child_ibsec);
 
 				/*
 				 * Don't try to create indexes on foreign tables, though. Skip
@@ -1418,9 +1414,7 @@ DefineIndex(ParseState *pstate,
 								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
 										   RelationGetRelationName(rel))));
 
-					AtEOXact_GUC(false, child_save_nestlevel);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					disable_index_build_security(&child_ibsec);
 					table_close(childrel, lockmode);
 					continue;
 				}
@@ -1505,9 +1499,7 @@ DefineIndex(ParseState *pstate,
 				}
 
 				list_free(childidxs);
-				AtEOXact_GUC(false, child_save_nestlevel);
-				SetUserIdAndSecContext(child_save_userid,
-									   child_save_sec_context);
+				disable_index_build_security(&child_ibsec);
 				table_close(childrel, NoLock);
 
 				/*
@@ -1534,7 +1526,7 @@ DefineIndex(ParseState *pstate,
 					 * Recurse as the starting user ID.  Callee will use that
 					 * for permission checks, then switch again.
 					 */
-					Assert(GetUserId() == child_save_userid);
+					Assert(GetUserId() == child_ibsec.userid);
 					SetUserIdAndSecContext(root_save_userid,
 										   root_save_sec_context);
 					childAddr =
@@ -1547,8 +1539,8 @@ DefineIndex(ParseState *pstate,
 									is_alter_table, check_rights,
 									check_not_in_use,
 									skip_build, quiet);
-					SetUserIdAndSecContext(child_save_userid,
-										   child_save_sec_context);
+					SetUserIdAndSecContext(child_ibsec.userid,
+										   child_ibsec.sec_context);
 
 					/*
 					 * Check if the index just created is valid or not, as it
@@ -4051,27 +4043,19 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		Oid			newIndexId;
 		Relation	indexRel;
 		Relation	heapRel;
-		Oid			save_userid;
-		int			save_sec_context;
-		int			save_nestlevel;
 		Relation	newIndexRel;
 		LockRelId  *lockrelid;
 		Oid			tablespaceid;
+		IndexBuildSecurity ibsec;
 
 		indexRel = index_open(idx->indexId, ShareUpdateExclusiveLock);
 		heapRel = table_open(indexRel->rd_index->indrelid,
 							 ShareUpdateExclusiveLock);
 
 		/*
-		 * Switch to the table owner's userid, so that any index functions are
-		 * run as that user.  Also lock down security-restricted operations
-		 * and arrange to make GUC variable changes local to this command.
+		 * Prevent index functions from doing what they are not supposed to.
 		 */
-		GetUserIdAndSecContext(&save_userid, &save_sec_context);
-		SetUserIdAndSecContext(heapRel->rd_rel->relowner,
-							   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-		save_nestlevel = NewGUCNestLevel();
-		RestrictSearchPath();
+		enable_index_build_security(heapRel->rd_rel->relowner, &ibsec);
 
 		/* determine safety of this index for set_indexsafe_procflags */
 		idx->safe = (RelationGetIndexExpressions(indexRel) == NIL &&
@@ -4159,11 +4143,8 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 		index_close(indexRel, NoLock);
 		index_close(newIndexRel, NoLock);
 
-		/* Roll back any GUC changes executed by index functions */
-		AtEOXact_GUC(false, save_nestlevel);
-
-		/* Restore userid and security context */
-		SetUserIdAndSecContext(save_userid, save_sec_context);
+		/* Relax the restrictions imposed above. */
+		disable_index_build_security(&ibsec);
 
 		table_close(heapRel, NoLock);
 
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 0bf19d07db5..1ad453a39a0 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -514,13 +514,11 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	Oid			tableOid = RelationGetRelid(OldHeap);
 	Relation	index;
 	LOCKMODE	lmode;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	bool		verbose = ((params->options & CLUOPT_VERBOSE) != 0);
 	bool		recheck = ((params->options & CLUOPT_RECHECK) != 0);
 	bool		concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
 	Oid			ident_idx = InvalidOid;
+	IndexBuildSecurity ibsec;
 
 	/* Determine the lock mode to use. */
 	lmode = RepackLockLevel(concurrent);
@@ -539,15 +537,9 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	pgstat_progress_update_param(PROGRESS_REPACK_COMMAND, cmd);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(OldHeap->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(OldHeap->rd_rel->relowner, &ibsec);
 
 	/*
 	 * Recheck that the relation is still what it was when we started.
@@ -557,7 +549,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	 * not-previously-clustered index.
 	 */
 	if (recheck &&
-		!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
+		!cluster_rel_recheck(cmd, OldHeap, indexOid, GetUserId(),
 							 lmode, params->options))
 		goto out;
 
@@ -681,11 +673,8 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 		rebuild_relation(OldHeap, index, verbose, ident_idx);
 
 out:
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	pgstat_progress_end_command();
 }
@@ -1234,7 +1223,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
 	}
 }
 
-
 /*
  * Create the transient table that will be filled with new data during
  * CLUSTER, ALTER TABLE, and similar operations.  The transient table
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index cb93c3e935a..d691b317011 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -23762,9 +23762,7 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	Oid			defaultPartOid;
 	Oid			existingRelid;
 	Oid			ownerId = InvalidOid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * Check ownership of merged partitions - partitions with different owners
@@ -23896,18 +23894,9 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	newPartRel = createPartitionTable(wqueue, cmd->name, rel, ownerId);
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also, lockdown security-restricted operations and
-	 * arrange to make GUC variable changes local to this command.
-	 *
-	 * Need to do it after determining the namespace in the
-	 * createPartitionTable() call.
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(ownerId,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(ownerId, &ibsec);
 
 	/* Copy data from merged partitions to the new partition. */
 	MergePartitionsMoveRows(wqueue, mergingPartitions, newPartRel);
@@ -23944,11 +23933,8 @@ ATExecMergePartitions(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	/* Keep the lock until commit. */
 	table_close(newPartRel, NoLock);
 
-	/* Roll back any GUC changes executed by index functions. */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore the userid and security context. */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 38539a6fd3d..5d1cbc382fa 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -34,6 +34,7 @@
 #include "access/tableam.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "catalog/index.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
@@ -2017,10 +2018,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 	LockRelId	lockrelid;
 	Oid			priv_relid;
 	Oid			toast_relid;
-	Oid			save_userid;
-	int			save_sec_context;
-	int			save_nestlevel;
 	VacuumParams toast_vacuum_params;
+	IndexBuildSecurity ibsec;
 
 	/*
 	 * This function scribbles on the parameters, so make a copy early to
@@ -2270,16 +2269,9 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 		toast_relid = InvalidOid;
 
 	/*
-	 * Switch to the table owner's userid, so that any index functions are run
-	 * as that user.  Also lock down security-restricted operations and
-	 * arrange to make GUC variable changes local to this command. (This is
-	 * unnecessary, but harmless, for lazy VACUUM.)
+	 * Prevent index functions from doing what they are not supposed to.
 	 */
-	GetUserIdAndSecContext(&save_userid, &save_sec_context);
-	SetUserIdAndSecContext(rel->rd_rel->relowner,
-						   save_sec_context | SECURITY_RESTRICTED_OPERATION);
-	save_nestlevel = NewGUCNestLevel();
-	RestrictSearchPath();
+	enable_index_build_security(rel->rd_rel->relowner, &ibsec);
 
 	/*
 	 * If PROCESS_MAIN is set (the default), it's time to vacuum the main
@@ -2310,11 +2302,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
 			table_relation_vacuum(rel, &params, bstrategy);
 	}
 
-	/* Roll back any GUC changes executed by index functions */
-	AtEOXact_GUC(false, save_nestlevel);
-
-	/* Restore userid and security context */
-	SetUserIdAndSecContext(save_userid, save_sec_context);
+	/* Relax the restrictions imposed above. */
+	disable_index_build_security(&ibsec);
 
 	/* all done with this class, but hold lock until commit */
 	if (rel)
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index 9aee8226347..dd9ae8119e5 100644
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -172,6 +172,16 @@ extern void reindex_index(const ReindexStmt *stmt, Oid indexId,
 extern bool reindex_relation(const ReindexStmt *stmt, Oid relid, int flags,
 							 const ReindexParams *params);
 
+typedef struct IndexBuildSecurity
+{
+	Oid			userid;
+	int			sec_context;
+	int			nestlevel;
+} IndexBuildSecurity;
+
+extern void enable_index_build_security(Oid userid, IndexBuildSecurity *sec);
+extern void disable_index_build_security(IndexBuildSecurity *sec);
+
 extern bool ReindexIsProcessingHeap(Oid heapOid);
 extern bool ReindexIsProcessingIndex(Oid indexOid);
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 25ac7079099..0ec534d15d7 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1327,6 +1327,7 @@ IndexAttachInfo
 IndexAttrBitmapKind
 IndexBuildCallback
 IndexBuildResult
+IndexBuildSecurity
 IndexBulkDeleteCallback
 IndexBulkDeleteResult
 IndexClause
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v02-0006-Use-separate-transactions-for-catalog-changes.patch



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end of thread, other threads:[~2026-07-15 08:37 UTC | newest]

Thread overview: 284+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2026-04-07 20:30 [PATCH v4 1/1] remove toast reloptions Nathan Bossart <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-06-16 11:54 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>
2026-07-15 08:37 [PATCH 5/8] Simplify the way restrictions are imposed on index functions. Antonin Houska <[email protected]>

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