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[PATCH 3/6] Move conversion of a "historic" to MVCC snapshot to a separate function.
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* [PATCH 3/6] Move conversion of a "historic" to MVCC snapshot to a separate function.
@ 2026-01-08 16:47 Antonin Houska <[email protected]>
  0 siblings, 0 replies; 106+ messages in thread

From: Antonin Houska @ 2026-01-08 16:47 UTC (permalink / raw)

The conversion is now handled by SnapBuildMVCCFromHistoric(). REPACK
CONCURRENTLY will also need it.
---
 src/backend/replication/logical/snapbuild.c | 57 +++++++++++++++++----
 src/backend/utils/time/snapmgr.c            |  3 +-
 src/include/replication/snapbuild.h         |  1 +
 src/include/utils/snapmgr.h                 |  1 +
 4 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index 7f79621b57e..95f230f8e9b 100644
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -440,10 +440,7 @@ Snapshot
 SnapBuildInitialSnapshot(SnapBuild *builder)
 {
 	Snapshot	snap;
-	TransactionId xid;
 	TransactionId safeXid;
-	TransactionId *newxip;
-	int			newxcnt = 0;
 
 	Assert(XactIsoLevel == XACT_REPEATABLE_READ);
 	Assert(builder->building_full_snapshot);
@@ -485,7 +482,33 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 
 	MyProc->xmin = snap->xmin;
 
-	/* allocate in transaction context */
+	/* Convert the historic snapshot to MVCC snapshot. */
+	return SnapBuildMVCCFromHistoric(snap, true);
+}
+
+/*
+ * Turn a historic MVCC snapshot into an ordinary MVCC snapshot.
+ *
+ * Unlike a regular (non-historic) MVCC snapshot, the 'xip' array of this
+ * snapshot contains not only running main transactions, but also their
+ * subtransactions. On the other hand, 'subxip' will usually be empty. This
+ * difference does not affect the result of XidInMVCCSnapshot() because it
+ * searches both in 'xip' and 'subxip'.
+ *
+ * Pass true for 'in_place' if you don't care about modifying the source
+ * snapshot. If you need a new instance, and one that was allocated as a
+ * single chunk of memory, pass false.
+ */
+Snapshot
+SnapBuildMVCCFromHistoric(Snapshot snapshot, bool in_place)
+{
+	TransactionId xid;
+	TransactionId *oldxip = snapshot->xip;
+	uint32		oldxcnt = snapshot->xcnt;
+	TransactionId *newxip;
+	int			newxcnt = 0;
+	Snapshot	result;
+
 	newxip = palloc_array(TransactionId, GetMaxSnapshotXidCount());
 
 	/*
@@ -494,7 +517,7 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 	 * classical snapshot by marking all non-committed transactions as
 	 * in-progress. This can be expensive.
 	 */
-	for (xid = snap->xmin; NormalTransactionIdPrecedes(xid, snap->xmax);)
+	for (xid = snapshot->xmin; NormalTransactionIdPrecedes(xid, snapshot->xmax);)
 	{
 		void	   *test;
 
@@ -502,7 +525,7 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 		 * Check whether transaction committed using the decoding snapshot
 		 * meaning of ->xip.
 		 */
-		test = bsearch(&xid, snap->xip, snap->xcnt,
+		test = bsearch(&xid, snapshot->xip, snapshot->xcnt,
 					   sizeof(TransactionId), xidComparator);
 
 		if (test == NULL)
@@ -519,11 +542,25 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 	}
 
 	/* adjust remaining snapshot fields as needed */
-	snap->snapshot_type = SNAPSHOT_MVCC;
-	snap->xcnt = newxcnt;
-	snap->xip = newxip;
+	snapshot->xcnt = newxcnt;
+	snapshot->xip = newxip;
+
+	if (in_place)
+		result = snapshot;
+	else
+	{
+		result = CopySnapshot(snapshot);
+
+		/* Restore the original values so the source is intact. */
+		snapshot->xip = oldxip;
+		snapshot->xcnt = oldxcnt;
+
+		/* newxip has been copied */
+		pfree(newxip);
+	}
+	result->snapshot_type = SNAPSHOT_MVCC;
 
-	return snap;
+	return result;
 }
 
 /*
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 2e6197f5f35..3af1b366adf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -213,7 +213,6 @@ typedef struct ExportedSnapshot
 static List *exportedSnapshots = NIL;
 
 /* Prototypes for local functions */
-static Snapshot CopySnapshot(Snapshot snapshot);
 static void UnregisterSnapshotNoOwner(Snapshot snapshot);
 static void FreeSnapshot(Snapshot snapshot);
 static void SnapshotResetXmin(void);
@@ -604,7 +603,7 @@ SetTransactionSnapshot(Snapshot sourcesnap, VirtualTransactionId *sourcevxid,
  * The copy is palloc'd in TopTransactionContext and has initial refcounts set
  * to 0.  The returned snapshot has the copied flag set.
  */
-static Snapshot
+Snapshot
 CopySnapshot(Snapshot snapshot)
 {
 	Snapshot	newsnap;
diff --git a/src/include/replication/snapbuild.h b/src/include/replication/snapbuild.h
index ccded021433..34383dea776 100644
--- a/src/include/replication/snapbuild.h
+++ b/src/include/replication/snapbuild.h
@@ -73,6 +73,7 @@ extern void FreeSnapshotBuilder(SnapBuild *builder);
 extern void SnapBuildSnapDecRefcount(Snapshot snap);
 
 extern Snapshot SnapBuildInitialSnapshot(SnapBuild *builder);
+extern Snapshot SnapBuildMVCCFromHistoric(Snapshot snapshot, bool in_place);
 extern const char *SnapBuildExportSnapshot(SnapBuild *builder);
 extern void SnapBuildClearExportedSnapshot(void);
 extern void SnapBuildResetExportedSnapshotState(void);
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index b8c01a291a1..de824945f0b 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -63,6 +63,7 @@ extern Snapshot GetTransactionSnapshot(void);
 extern Snapshot GetLatestSnapshot(void);
 extern void SnapshotSetCommandId(CommandId curcid);
 
+extern Snapshot CopySnapshot(Snapshot snapshot);
 extern Snapshot GetCatalogSnapshot(Oid relid);
 extern Snapshot GetNonHistoricCatalogSnapshot(Oid relid);
 extern void InvalidateCatalogSnapshot(void);
-- 
2.47.3


--=-=-=
Content-Type: text/plain
Content-Disposition: attachment;
 filename=v29-0004-Add-CONCURRENTLY-option-to-REPACK-command.patch



^ permalink  raw  reply  [nested|flat] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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] 106+ 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; 106+ 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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2026-01-08 16:47 [PATCH 3/6] Move conversion of a "historic" to MVCC snapshot to a separate function. 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]>

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