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

diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index 1db3ef69d22fc19784927dffd6fc33e04f97f283..40c7e06d0d0f25197733109eae85e7ac14e2d8e9 100644 (file)
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -59,7 +59,7 @@ 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;
@@ -169,6 +169,21 @@ 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.
     */

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 6d3565b274918bfc396a78ae4632ef87168284cb..3ba65a33a124126946164cbf052edbf0143e08a9 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -9249,7 +9249,7 @@ 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 0dd797cb2b5bfa2e7ab26a82d5b8ebaddf29367d..2be41afc2d3f8d03172ee87f7c8cc6edc8655858 100644 (file)
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1898,7 +1898,7 @@ ProcessUtilitySlow(ParseState *pstate,
                    /* Run parse analysis ... */
                    stmt = transformStatsStmt(relid, stmt, queryString);
 
-                   address = CreateStatistics(stmt);
+                   address = CreateStatistics(stmt, true);
                }
                break;
 

diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 29c511e319693bd748a8aef59f372b9c3c760d8b..74ca50ac8e7cd3c34c0ecd592925ba22d550c8f5 100644 (file)
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -81,7 +81,7 @@ extern void RemoveOperatorById(Oid operOid);
 extern ObjectAddress AlterOperator(AlterOperatorStmt *stmt);
 
 /* commands/statscmds.c */
-extern ObjectAddress CreateStatistics(CreateStatsStmt *stmt);
+extern ObjectAddress CreateStatistics(CreateStatsStmt *stmt, bool check_rights);
 extern ObjectAddress AlterStatistics(AlterStatsStmt *stmt);
 extern void RemoveStatisticsById(Oid statsOid);
 extern void RemoveStatisticsDataById(Oid statsOid, bool inh);

diff --git a/src/test/regress/expected/stats_ext.out b/src/test/regress/expected/stats_ext.out
index a3669f7aaa22414e4b7059d665aa294fed41a1a3..ec92d784680c32e17809ee942ca76cc92df2e3a6 100644 (file)
--- a/src/test/regress/expected/stats_ext.out
+++ b/src/test/regress/expected/stats_ext.out
@@ -3409,6 +3409,41 @@ SELECT statistics_name, most_common_vals FROM pg_stats_ext_exprs x
  s_expr          | {1}
 (2 rows)
 
+-- CREATE STATISTICS checks for CREATE on the schema
+RESET SESSION AUTHORIZATION;
+CREATE SCHEMA sts_sch1 CREATE TABLE sts_sch1.tbl (a INT, b INT, c INT GENERATED ALWAYS AS (b * 2) STORED);
+CREATE SCHEMA sts_sch2;
+GRANT USAGE ON SCHEMA sts_sch1, sts_sch2 TO regress_stats_user1;
+ALTER TABLE sts_sch1.tbl OWNER TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+ERROR:  permission denied for schema sts_sch1
+CREATE STATISTICS sts_sch2.fail ON a, b, c FROM sts_sch1.tbl;
+ERROR:  permission denied for schema sts_sch2
+RESET SESSION AUTHORIZATION;
+GRANT CREATE ON SCHEMA sts_sch1 TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+CREATE STATISTICS sts_sch2.fail ON a, b, c FROM sts_sch1.tbl;
+ERROR:  permission denied for schema sts_sch2
+RESET SESSION AUTHORIZATION;
+REVOKE CREATE ON SCHEMA sts_sch1 FROM regress_stats_user1;
+GRANT CREATE ON SCHEMA sts_sch2 TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+ERROR:  permission denied for schema sts_sch1
+CREATE STATISTICS sts_sch2.pass1 ON a, b, c FROM sts_sch1.tbl;
+RESET SESSION AUTHORIZATION;
+GRANT CREATE ON SCHEMA sts_sch1, sts_sch2 TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+CREATE STATISTICS sts_sch2.pass2 ON a, b, c FROM sts_sch1.tbl;
+-- re-creating statistics via ALTER TABLE bypasses checks for CREATE on schema
+RESET SESSION AUTHORIZATION;
+REVOKE CREATE ON SCHEMA sts_sch1, sts_sch2 FROM regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+ALTER TABLE sts_sch1.tbl ALTER COLUMN a TYPE SMALLINT;
+ALTER TABLE sts_sch1.tbl ALTER COLUMN c SET EXPRESSION AS (a * 3);
 -- Tidy up
 DROP OPERATOR <<< (int, int);
 DROP FUNCTION op_leak(int, int);
@@ -3421,4 +3456,6 @@ NOTICE:  drop cascades to 3 other objects
 DETAIL:  drop cascades to table tststats.priv_test_parent_tbl
 drop cascades to table tststats.priv_test_tbl
 drop cascades to view tststats.priv_test_view
+DROP SCHEMA sts_sch1, sts_sch2 CASCADE;
+NOTICE:  drop cascades to table sts_sch1.tbl
 DROP USER regress_stats_user1;

diff --git a/src/test/regress/sql/stats_ext.sql b/src/test/regress/sql/stats_ext.sql
index 95811beef0cf14f71b63536c6ad05e60d6308804..0c20415723ba23f4f350dcebec1d7aa71f1440a3 100644 (file)
--- a/src/test/regress/sql/stats_ext.sql
+++ b/src/test/regress/sql/stats_ext.sql
@@ -1740,6 +1740,39 @@ SELECT statistics_name, most_common_vals FROM pg_stats_ext x
 SELECT statistics_name, most_common_vals FROM pg_stats_ext_exprs x
     WHERE tablename = 'stats_ext_tbl' ORDER BY ROW(x.*);
 
+-- CREATE STATISTICS checks for CREATE on the schema
+RESET SESSION AUTHORIZATION;
+CREATE SCHEMA sts_sch1 CREATE TABLE sts_sch1.tbl (a INT, b INT, c INT GENERATED ALWAYS AS (b * 2) STORED);
+CREATE SCHEMA sts_sch2;
+GRANT USAGE ON SCHEMA sts_sch1, sts_sch2 TO regress_stats_user1;
+ALTER TABLE sts_sch1.tbl OWNER TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+CREATE STATISTICS sts_sch2.fail ON a, b, c FROM sts_sch1.tbl;
+RESET SESSION AUTHORIZATION;
+GRANT CREATE ON SCHEMA sts_sch1 TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+CREATE STATISTICS sts_sch2.fail ON a, b, c FROM sts_sch1.tbl;
+RESET SESSION AUTHORIZATION;
+REVOKE CREATE ON SCHEMA sts_sch1 FROM regress_stats_user1;
+GRANT CREATE ON SCHEMA sts_sch2 TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+CREATE STATISTICS sts_sch2.pass1 ON a, b, c FROM sts_sch1.tbl;
+RESET SESSION AUTHORIZATION;
+GRANT CREATE ON SCHEMA sts_sch1, sts_sch2 TO regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+CREATE STATISTICS ON a, b, c FROM sts_sch1.tbl;
+CREATE STATISTICS sts_sch2.pass2 ON a, b, c FROM sts_sch1.tbl;
+
+-- re-creating statistics via ALTER TABLE bypasses checks for CREATE on schema
+RESET SESSION AUTHORIZATION;
+REVOKE CREATE ON SCHEMA sts_sch1, sts_sch2 FROM regress_stats_user1;
+SET SESSION AUTHORIZATION regress_stats_user1;
+ALTER TABLE sts_sch1.tbl ALTER COLUMN a TYPE SMALLINT;
+ALTER TABLE sts_sch1.tbl ALTER COLUMN c SET EXPRESSION AS (a * 3);
+
 -- Tidy up
 DROP OPERATOR <<< (int, int);
 DROP FUNCTION op_leak(int, int);
@@ -1748,4 +1781,5 @@ DROP FUNCTION op_leak(record, record);
 RESET SESSION AUTHORIZATION;
 DROP TABLE stats_ext_tbl;
 DROP SCHEMA tststats CASCADE;
+DROP SCHEMA sts_sch1, sts_sch2 CASCADE;
 DROP USER regress_stats_user1;