Check for CREATE privilege on the schema in CREATE STATISTICS.

This omission allowed table owners to create statistics in any
schema, potentially leading to unexpected naming conflicts.  For
ALTER TABLE commands that require re-creating statistics objects,
skip this check in case the user has since lost CREATE on the
schema.  The addition of a second parameter to CreateStatistics()
breaks ABI compatibility, but we are unaware of any impacted
third-party code.

Reported-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Co-authored-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Security: CVE-2025-12817
Backpatch-through: 13

3 files changed, 18 insertions, 3 deletions

diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index 27bf67e7c4b..0cf0ea43f19 100644
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -60,7 +60,7 @@ compare_int16(const void *a, const void *b)
  *		CREATE STATISTICS
  */
 ObjectAddress
-CreateStatistics(CreateStatsStmt *stmt)
+CreateStatistics(CreateStatsStmt *stmt, bool check_rights)
 {
 	int16		attnums[STATS_MAX_DIMENSIONS];
 	int			nattnums = 0;
@@ -171,6 +171,21 @@ CreateStatistics(CreateStatsStmt *stmt)
 	namestrcpy(&stxname, namestr);
 
 	/*
+	 * Check we have creation rights in target namespace.  Skip check if
+	 * caller doesn't want it.
+	 */
+	if (check_rights)
+	{
+		AclResult	aclresult;
+
+		aclresult = object_aclcheck(NamespaceRelationId, namespaceId,
+									GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_SCHEMA,
+						   get_namespace_name(namespaceId));
+	}
+
+	/*
 	 * Deal with the possibility that the statistics object already exists.
 	 */
 	if (SearchSysCacheExists2(STATEXTNAMENSP,
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 3aac459e483..23ebaa3f230 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -9682,7 +9682,7 @@ ATExecAddStatistics(AlteredTableInfo *tab, Relation rel,
 	/* The CreateStatsStmt has already been through transformStatsStmt */
 	Assert(stmt->transformed);
 
-	address = CreateStatistics(stmt);
+	address = CreateStatistics(stmt, !is_rebuild);
 
 	return address;
 }
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 082967c0a86..d18a3a60a46 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1900,7 +1900,7 @@ ProcessUtilitySlow(ParseState *pstate,
 					/* Run parse analysis ... */
 					stmt = transformStatsStmt(relid, stmt, queryString);
 
-					address = CreateStatistics(stmt);
+					address = CreateStatistics(stmt, true);
 				}
 				break;