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mirror of https://github.com/postgres/postgres.git synced 2026-10-23 13:29:09 +03:00

Return nulls honestly in aggregate "combine" functions.

numeric_combine() and several other state-combining functions for
aggregates cheated for the case of both inputs being NULL: they
returned a null pointer without bothering to mark it as a SQL NULL.
This was harmless in the expected usage where the result would be
passed to the same combine function or a related aggregate final
function.  But it's bad news from a security standpoint, because
now that value can be passed to an internal-accepting function
even if said function is strict.  While a previous patch prevented
such queries from being issued, it seems like good defense-in-depth
to expend the few additional lines of code needed to do this properly.
Comparable functions such as array_agg_combine() already do so.

Reported-by: Amy Burnett (OpenAI Codex Security)
Author: Tom Lane <tgl@sss.pgh.pa.us>
Backpatch-through: 14
Security: CVE-2026-14680
This commit is contained in:
Tom Lane
2026-08-10 06:38:11 -07:00
committed by Noah Misch
parent 54649de65f
commit 722695db18
2 changed files with 40 additions and 0 deletions

View File

@@ -5176,7 +5176,15 @@ numeric_combine(PG_FUNCTION_ARGS)
state2 = PG_ARGISNULL(1) ? NULL : (NumericAggState *) PG_GETARG_POINTER(1);
if (state2 == NULL)
{
/*
* NULL state2 is easy, just return state1, which we know is already
* in the agg_context
*/
if (state1 == NULL)
PG_RETURN_NULL();
PG_RETURN_POINTER(state1);
}
/* manually copy all fields from state2 to state1 */
if (state1 == NULL)
@@ -5268,7 +5276,15 @@ numeric_avg_combine(PG_FUNCTION_ARGS)
state2 = PG_ARGISNULL(1) ? NULL : (NumericAggState *) PG_GETARG_POINTER(1);
if (state2 == NULL)
{
/*
* NULL state2 is easy, just return state1, which we know is already
* in the agg_context
*/
if (state1 == NULL)
PG_RETURN_NULL();
PG_RETURN_POINTER(state1);
}
/* manually copy all fields from state2 to state1 */
if (state1 == NULL)
@@ -5752,7 +5768,15 @@ numeric_poly_combine(PG_FUNCTION_ARGS)
state2 = PG_ARGISNULL(1) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(1);
if (state2 == NULL)
{
/*
* NULL state2 is easy, just return state1, which we know is already
* in the agg_context
*/
if (state1 == NULL)
PG_RETURN_NULL();
PG_RETURN_POINTER(state1);
}
/* manually copy all fields from state2 to state1 */
if (state1 == NULL)
@@ -5955,7 +5979,15 @@ int8_avg_combine(PG_FUNCTION_ARGS)
state2 = PG_ARGISNULL(1) ? NULL : (PolyNumAggState *) PG_GETARG_POINTER(1);
if (state2 == NULL)
{
/*
* NULL state2 is easy, just return state1, which we know is already
* in the agg_context
*/
if (state1 == NULL)
PG_RETURN_NULL();
PG_RETURN_POINTER(state1);
}
/* manually copy all fields from state2 to state1 */
if (state1 == NULL)

View File

@@ -4094,7 +4094,15 @@ interval_avg_combine(PG_FUNCTION_ARGS)
state2 = PG_ARGISNULL(1) ? NULL : (IntervalAggState *) PG_GETARG_POINTER(1);
if (state2 == NULL)
{
/*
* NULL state2 is easy, just return state1, which we know is already
* in the agg_context
*/
if (state1 == NULL)
PG_RETURN_NULL();
PG_RETURN_POINTER(state1);
}
if (state1 == NULL)
{