postgres.git / summary / log / commit / refs
commit 4da71fc37a20eb7bfc339197ad6c9b95af46c59c
Author: Richard Guo <rguo@postgresql.org>
Date: Thu Apr 09 10:28:33 2026 +0000
Fix integer overflow in nodeWindowAgg.c
In nodeWindowAgg.c, the calculations for frame start and end positions
in ROWS and GROUPS modes were performed using simple integer addition.
If a user-supplied offset was sufficiently large (close to INT64_MAX),
adding it to the current row or group index could cause a signed
integer overflow, wrapping the result to a negative number.
This led to incorrect behavior where frame boundaries that should have
extended indefinitely (or beyond the partition end) were treated as
falling at the first row, or where valid rows were incorrectly marked
as out-of-frame. Depending on the specific query and data, these
overflows can result in incorrect query results, execution errors, or
assertion failures.
To fix, use overflow-aware integer addition (ie, pg_add_s64_overflow)
to check for overflows during these additions. If an overflow is
detected, the boundary is now clamped to INT64_MAX. This ensures the
logic correctly treats the boundary as extending to the end of the
partition.
Bug: #19405
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Discussion: https://postgr.es/m/19405-1ecf025dda171555@postgresql.org
Backpatch-through: 14
src/backend/executor/nodeWindowAgg.c | 62 +++++++++++++++++++++---
src/test/regress/expected/window.out | 91 ++++++++++++++++++++++++++++++++++++
src/test/regress/sql/window.sql | 26 +++++++++++
3 files changed, 172 insertions(+), 7 deletions(-)
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 3e7436f4918..6bbe7314f51 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -37,6 +37,7 @@
#include "catalog/objectaccess.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_proc.h"
+#include "common/int.h"
#include "executor/executor.h"
#include "executor/nodeWindowAgg.h"
#include "miscadmin.h"
@@ -1423,12 +1424,21 @@ row_is_in_frame(WindowAggState *winstate, int64 pos, TupleTableSlot *slot)
if (frameOptions & FRAMEOPTION_ROWS)
{
int64 offset = DatumGetInt64(winstate->endOffsetValue);
+ int64 frameendpos = 0;
/* rows after current row + offset are out of frame */
if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
offset = -offset;
- if (pos > winstate->currentpos + offset)
+ /*
+ * If we have an overflow, it means the frame end is beyond the
+ * range of int64. Since currentpos >= 0, this can only be a
+ * positive overflow. We treat this as meaning that the frame
+ * extends to end of partition.
+ */
+ if (!pg_add_s64_overflow(winstate->currentpos, offset,
+ &frameendpos) &&
+ pos > frameendpos)
return -1;
}
else if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
@@ -1563,7 +1573,16 @@ update_frameheadpos(WindowAggState *winstate)
if (frameOptions & FRAMEOPTION_START_OFFSET_PRECEDING)
offset = -offset;
- winstate->frameheadpos = winstate->currentpos + offset;
+ /*
+ * If we have an overflow, it means the frame head is beyond the
+ * range of int64. Since currentpos >= 0, this can only be a
+ * positive overflow. We treat this as being beyond end of
+ * partition.
+ */
+ if (pg_add_s64_overflow(winstate->currentpos, offset,
+ &winstate->frameheadpos))
+ winstate->frameheadpos = PG_INT64_MAX;
+
/* frame head can't go before first row */
if (winstate->frameheadpos < 0)
winstate->frameheadpos = 0;
@@ -1675,12 +1694,21 @@ update_frameheadpos(WindowAggState *winstate)
* framehead_slot empty.
*/
int64 offset = DatumGetInt64(winstate->startOffsetValue);
- int64 minheadgroup;
+ int64 minheadgroup = 0;
if (frameOptions & FRAMEOPTION_START_OFFSET_PRECEDING)
minheadgroup = winstate->currentgroup - offset;
else
- minheadgroup = winstate->currentgroup + offset;
+ {
+ /*
+ * If we have an overflow, it means the target group is beyond
+ * the range of int64. We treat this as "infinity", which
+ * ensures the loop below advances to end of partition.
+ */
+ if (pg_add_s64_overflow(winstate->currentgroup, offset,
+ &minheadgroup))
+ minheadgroup = PG_INT64_MAX;
+ }
tuplestore_select_read_pointer(winstate->buffer,
winstate->framehead_ptr);
@@ -1817,7 +1845,18 @@ update_frametailpos(WindowAggState *winstate)
if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
offset = -offset;
- winstate->frametailpos = winstate->currentpos + offset + 1;
+ /*
+ * If we have an overflow, it means the frame tail is beyond the
+ * range of int64. Since currentpos >= 0, this can only be a
+ * positive overflow. We treat this as being beyond end of
+ * partition.
+ */
+ if (pg_add_s64_overflow(winstate->currentpos, offset,
+ &winstate->frametailpos) ||
+ pg_add_s64_overflow(winstate->frametailpos, 1,
+ &winstate->frametailpos))
+ winstate->frametailpos = PG_INT64_MAX;
+
/* smallest allowable value of frametailpos is 0 */
if (winstate->frametailpos < 0)
winstate->frametailpos = 0;
@@ -1929,12 +1968,21 @@ update_frametailpos(WindowAggState *winstate)
* leave frametailpos = end+1 and frametail_slot empty.
*/
int64 offset = DatumGetInt64(winstate->endOffsetValue);
- int64 maxtailgroup;
+ int64 maxtailgroup = 0;
if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
maxtailgroup = winstate->currentgroup - offset;
else
- maxtailgroup = winstate->currentgroup + offset;
+ {
+ /*
+ * If we have an overflow, it means the target group is beyond
+ * the range of int64. We treat this as "infinity", which
+ * ensures the loop below advances to end of partition.
+ */
+ if (pg_add_s64_overflow(winstate->currentgroup, offset,
+ &maxtailgroup))
+ maxtailgroup = PG_INT64_MAX;
+ }
tuplestore_select_read_pointer(winstate->buffer,
winstate->frametail_ptr);
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index d626591a05d..b240cd468f7 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -1343,6 +1343,97 @@ SELECT pg_get_viewdef('v_window');
FROM generate_series(now(), (now() + '@ 100 days'::interval), '@ 1 hour'::interval) i(i);
(1 row)
+-- test overflow frame specifications
+SELECT sum(unique1) over (rows between current row and 9223372036854775807 following exclude current row),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+ sum | unique1 | four
+-----+---------+------
+ 41 | 4 | 0
+ 39 | 2 | 2
+ 38 | 1 | 1
+ 32 | 6 | 2
+ 23 | 9 | 1
+ 15 | 8 | 0
+ 10 | 5 | 1
+ 7 | 3 | 3
+ 0 | 7 | 3
+ | 0 | 0
+(10 rows)
+
+SELECT sum(unique1) over (rows between 9223372036854775807 following and 1 following),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+ sum | unique1 | four
+-----+---------+------
+ | 4 | 0
+ | 2 | 2
+ | 1 | 1
+ | 6 | 2
+ | 9 | 1
+ | 8 | 0
+ | 5 | 1
+ | 3 | 3
+ | 7 | 3
+ | 0 | 0
+(10 rows)
+
+SELECT last_value(unique1) over (ORDER BY four rows between current row and 9223372036854775807 following exclude current row),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+ last_value | unique1 | four
+------------+---------+------
+ 7 | 0 | 0
+ 7 | 8 | 0
+ 7 | 4 | 0
+ 7 | 5 | 1
+ 7 | 9 | 1
+ 7 | 1 | 1
+ 7 | 6 | 2
+ 7 | 2 | 2
+ 7 | 3 | 3
+ | 7 | 3
+(10 rows)
+
+-- These test GROUPS mode with an offset large enough to cause overflow when
+-- added to currentgroup. Although the overflow doesn't produce visibly wrong
+-- results (due to the incremental nature of group pointer advancement), we
+-- still need to protect against it as signed integer overflow is undefined
+-- behavior in C.
+SELECT sum(unique1) over (ORDER BY four groups between current row and 9223372036854775807 following),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+ sum | unique1 | four
+-----+---------+------
+ 45 | 0 | 0
+ 45 | 8 | 0
+ 45 | 4 | 0
+ 33 | 5 | 1
+ 33 | 9 | 1
+ 33 | 1 | 1
+ 18 | 6 | 2
+ 18 | 2 | 2
+ 10 | 3 | 3
+ 10 | 7 | 3
+(10 rows)
+
+SELECT sum(unique1) over (ORDER BY four groups between 9223372036854775807 following and unbounded following),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+ sum | unique1 | four
+-----+---------+------
+ | 0 | 0
+ | 8 | 0
+ | 4 | 0
+ | 5 | 1
+ | 9 | 1
+ | 1 | 1
+ | 6 | 2
+ | 2 | 2
+ | 3 | 3
+ | 7 | 3
+(10 rows)
+
-- RANGE offset PRECEDING/FOLLOWING tests
SELECT sum(unique1) over (order by four range between 2::int8 preceding and 1::int2 preceding),
unique1, four
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index edf17e50a47..184756b16ff 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -326,6 +326,32 @@ CREATE TEMP VIEW v_window AS
SELECT pg_get_viewdef('v_window');
+-- test overflow frame specifications
+SELECT sum(unique1) over (rows between current row and 9223372036854775807 following exclude current row),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+
+SELECT sum(unique1) over (rows between 9223372036854775807 following and 1 following),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+
+SELECT last_value(unique1) over (ORDER BY four rows between current row and 9223372036854775807 following exclude current row),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+
+-- These test GROUPS mode with an offset large enough to cause overflow when
+-- added to currentgroup. Although the overflow doesn't produce visibly wrong
+-- results (due to the incremental nature of group pointer advancement), we
+-- still need to protect against it as signed integer overflow is undefined
+-- behavior in C.
+SELECT sum(unique1) over (ORDER BY four groups between current row and 9223372036854775807 following),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+
+SELECT sum(unique1) over (ORDER BY four groups between 9223372036854775807 following and unbounded following),
+ unique1, four
+FROM tenk1 WHERE unique1 < 10;
+
-- RANGE offset PRECEDING/FOLLOWING tests
SELECT sum(unique1) over (order by four range between 2::int8 preceding and 1::int2 preceding),
[parent: 07e833e3cff3]