Fix cache lookup hazards introduced by ff9618e.

nathan-bossart · nathan-bossart · commit 4dbdb82513b6 · 2023-06-22T15:48:20.000-07:00
ff9618e introduced has_partition_ancestor_privs(), which is used to check whether a user has MAINTAIN on any partition ancestors. This involves syscache lookups, and presently this function does not take any relation locks, so it is likely subject to the same kind of cache lookup failures that were fixed by 19de0ab. To fix this problem, this commit partially reverts ff9618e. Specifically, it removes the partition-related changes, including the has_partition_ancestor_privs() function mentioned above. This means that MAINTAIN on a partitioned table is no longer sufficient to perform maintenance commands on its partitions. This is more like how privileges for maintenance commands work on supported versions. Privileges are checked for each partition, so a command that flows down to all partitions might refuse to process them (e.g., if the current user doesn't have MAINTAIN on the partition). In passing, adjust a few related comments and error messages, and add a test for the privilege checks for CLUSTER on a partitioned table. Reviewed-by: Michael Paquier, Jeff Davis Discussion: https://postgr.es/m/20230613211246.GA219055%40nathanxps13
diff --git a/doc/src/sgml/ref/analyze.sgml b/doc/src/sgml/ref/analyze.sgml
@@ -190,10 +190,7 @@ ANALYZE [ VERBOSE ] [ <replaceable class="parameter">table_and_columns</replacea
    analyze all tables in their databases, except shared catalogs.
    (The restriction for shared catalogs means that a true database-wide
    <command>ANALYZE</command> can only be performed by superusers and roles
-   with privileges of <literal>pg_maintain</literal>.)  If a role has
-   permission to <command>ANALYZE</command> a partitioned table, it is also
-   permitted to <command>ANALYZE</command> each of its partitions, regardless
-   of whether the role has the aforementioned privileges on the partition.
+   with privileges of <literal>pg_maintain</literal>.)
    <command>ANALYZE</command> will skip over any tables that the calling user
    does not have permission to analyze.
   </para>
diff --git a/doc/src/sgml/ref/cluster.sgml b/doc/src/sgml/ref/cluster.sgml
@@ -137,10 +137,7 @@ CLUSTER [VERBOSE]
     on the table or be the table's owner, a superuser, or a role with
     privileges of the
     <link linkend="predefined-roles-table"><literal>pg_maintain</literal></link>
-    role.  If a role has permission to <command>CLUSTER</command> a partitioned
-    table, it is also permitted to <command>CLUSTER</command> each of its
-    partitions, regardless of whether the role has the aforementioned
-    privileges on the partition.  <command>CLUSTER</command> will skip over any
+    role.  <command>CLUSTER</command> will skip over any
     tables that the calling user does not have permission to cluster.
    </para>
 
diff --git a/doc/src/sgml/ref/lock.sgml b/doc/src/sgml/ref/lock.sgml
@@ -177,10 +177,7 @@ LOCK [ TABLE ] [ ONLY ] <replaceable class="parameter">name</replaceable> [ * ]
     MODE</literal> (or a less-conflicting mode as described in <xref
     linkend="explicit-locking"/>) is permitted. If a user has
     <literal>SELECT</literal> privileges on the table, <literal>ACCESS SHARE
-    MODE</literal> is permitted.  If a role has permission to lock a
-    partitioned table, it is also permitted to lock each of its partitions,
-    regardless of whether the role has the aforementioned privileges on the
-    partition.
+    MODE</literal> is permitted.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/reindex.sgml b/doc/src/sgml/ref/reindex.sgml
@@ -306,11 +306,7 @@ REINDEX [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] { DA
    indexes on shared catalogs will be skipped unless the user owns the
    catalog (which typically won't be the case), has privileges of the
    <literal>pg_maintain</literal> role, or has the <literal>MAINTAIN</literal>
-   privilege on the catalog.  If a role has permission to
-   <command>REINDEX</command> a partitioned table, it is also permitted to
-   <command>REINDEX</command> each of its partitions, regardless of whether the
-   role has the aforementioned privileges on the partition.  Of course,
-   superusers can always reindex anything.
+   privilege on the catalog.  Of course, superusers can always reindex anything.
   </para>
 
   <para>
diff --git a/doc/src/sgml/ref/vacuum.sgml b/doc/src/sgml/ref/vacuum.sgml
@@ -452,10 +452,7 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
     vacuum all tables in their databases, except shared catalogs.
     (The restriction for shared catalogs means that a true database-wide
     <command>VACUUM</command> can only be performed by superusers and roles
-    with privileges of <literal>pg_maintain</literal>.)  If a role has
-    permission to <command>VACUUM</command> a partitioned table, it is also
-    permitted to <command>VACUUM</command> each of its partitions, regardless
-    of whether the role has the aforementioned privileges on the partition.
+    with privileges of <literal>pg_maintain</literal>.)
     <command>VACUUM</command> will skip over any tables that the calling user
     does not have permission to vacuum.
    </para>
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
@@ -1694,10 +1694,13 @@ get_tables_to_cluster_partitioned(MemoryContext cluster_context, Oid indexOid)
 			continue;
 
 		/*
-		 * We already checked that the user has privileges to CLUSTER the
-		 * partitioned table when we locked it earlier, so there's no need to
-		 * check the privileges again here.
+		 * It's possible that the user does not have privileges to CLUSTER the
+		 * leaf partition despite having such privileges on the partitioned
+		 * table.  We skip any partitions which the user is not permitted to
+		 * CLUSTER.
 		 */
+		if (!cluster_is_permitted_for_relation(relid, GetUserId()))
+			continue;
 
 		/* Use a permanent memory context for the result list */
 		old_context = MemoryContextSwitchTo(cluster_context);
@@ -1720,8 +1723,7 @@ get_tables_to_cluster_partitioned(MemoryContext cluster_context, Oid indexOid)
 static bool
 cluster_is_permitted_for_relation(Oid relid, Oid userid)
 {
-	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK ||
-		has_partition_ancestor_privs(relid, userid, ACL_MAINTAIN))
+	if (pg_class_aclcheck(relid, userid, ACL_MAINTAIN) == ACLCHECK_OK)
 		return true;
 
 	ereport(WARNING,
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
@@ -2853,11 +2853,14 @@ RangeVarCallbackForReindexIndex(const RangeVar *relation,
 
 	/* Check permissions */
 	table_oid = IndexGetRelation(relId, true);
-	if (OidIsValid(table_oid) &&
-		pg_class_aclcheck(table_oid, GetUserId(), ACL_MAINTAIN) != ACLCHECK_OK &&
-		!has_partition_ancestor_privs(table_oid, GetUserId(), ACL_MAINTAIN))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX,
-					   relation->relname);
+	if (OidIsValid(table_oid))
+	{
+		AclResult	aclresult;
+
+		aclresult = pg_class_aclcheck(table_oid, GetUserId(), ACL_MAINTAIN);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_INDEX, relation->relname);
+	}
 
 	/* Lock heap before index to avoid deadlock. */
 	if (relId != oldRelId)
@@ -3064,18 +3067,12 @@ ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
 			continue;
 
 		/*
-		 * The table can be reindexed if the user has been granted MAINTAIN on
-		 * the table or one of its partition ancestors or the user is a
-		 * superuser, the table owner, or the database/schema owner (but in
-		 * the latter case, only if it's not a shared relation).
-		 * pg_class_aclcheck includes the superuser case, and depending on
-		 * objectKind we already know that the user has permission to run
-		 * REINDEX on this database or schema per the permission checks at the
-		 * beginning of this routine.
+		 * We already checked privileges on the database or schema, but we
+		 * further restrict reindexing shared catalogs to roles with the
+		 * MAINTAIN privilege on the relation.
 		 */
 		if (classtuple->relisshared &&
-			pg_class_aclcheck(relid, GetUserId(), ACL_MAINTAIN) != ACLCHECK_OK &&
-			!has_partition_ancestor_privs(relid, GetUserId(), ACL_MAINTAIN))
+			pg_class_aclcheck(relid, GetUserId(), ACL_MAINTAIN) != ACLCHECK_OK)
 			continue;
 
 		/*
diff --git a/src/backend/commands/lockcmds.c b/src/backend/commands/lockcmds.c
@@ -19,7 +19,6 @@
 #include "catalog/namespace.h"
 #include "catalog/pg_inherits.h"
 #include "commands/lockcmds.h"
-#include "commands/tablecmds.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
 #include "parser/parse_clause.h"
@@ -297,12 +296,5 @@ LockTableAclCheck(Oid reloid, LOCKMODE lockmode, Oid userid)
 
 	aclresult = pg_class_aclcheck(reloid, userid, aclmask);
 
-	/*
-	 * If this is a partition, check permissions of its ancestors if needed.
-	 */
-	if (aclresult != ACLCHECK_OK &&
-		has_partition_ancestor_privs(reloid, userid, ACL_MAINTAIN))
-		aclresult = ACLCHECK_OK;
-
 	return aclresult;
 }
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
@@ -16986,6 +16986,7 @@ RangeVarCallbackMaintainsTable(const RangeVar *relation,
 							   Oid relId, Oid oldRelId, void *arg)
 {
 	char		relkind;
+	AclResult	aclresult;
 
 	/* Nothing to do if the relation was not found. */
 	if (!OidIsValid(relId))
@@ -17006,36 +17007,9 @@ RangeVarCallbackMaintainsTable(const RangeVar *relation,
 				 errmsg("\"%s\" is not a table or materialized view", relation->relname)));
 
 	/* Check permissions */
-	if (pg_class_aclcheck(relId, GetUserId(), ACL_MAINTAIN) != ACLCHECK_OK &&
-		!has_partition_ancestor_privs(relId, GetUserId(), ACL_MAINTAIN))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_TABLE,
-					   relation->relname);
-}
-
-/*
- * If relid is a partition, returns whether userid has any of the privileges
- * specified in acl on any of its ancestors.  Otherwise, returns false.
- */
-bool
-has_partition_ancestor_privs(Oid relid, Oid userid, AclMode acl)
-{
-	List	   *ancestors;
-	ListCell   *lc;
-
-	if (!get_rel_relispartition(relid))
-		return false;
-
-	ancestors = get_partition_ancestors(relid);
-	foreach(lc, ancestors)
-	{
-		Oid			ancestor = lfirst_oid(lc);
-
-		if (OidIsValid(ancestor) &&
-			pg_class_aclcheck(ancestor, userid, acl) == ACLCHECK_OK)
-			return true;
-	}
-
-	return false;
+	aclresult = pg_class_aclcheck(relId, GetUserId(), ACL_MAINTAIN);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_TABLE, relation->relname);
 }
 
 /*
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
@@ -41,7 +41,6 @@
 #include "catalog/pg_namespace.h"
 #include "commands/cluster.h"
 #include "commands/defrem.h"
-#include "commands/tablecmds.h"
 #include "commands/vacuum.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
@@ -721,17 +720,12 @@ vacuum_is_permitted_for_relation(Oid relid, Form_pg_class reltuple,
 	/*----------
 	 * A role has privileges to vacuum or analyze the relation if any of the
 	 * following are true:
-	 *   - the role is a superuser
-	 *   - the role owns the relation
 	 *   - the role owns the current database and the relation is not shared
-	 *   - the role has been granted the MAINTAIN privilege on the relation
-	 *   - the role has privileges to vacuum/analyze any of the relation's
-	 *     partition ancestors
+	 *   - the role has the MAINTAIN privilege on the relation
 	 *----------
 	 */
 	if ((object_ownercheck(DatabaseRelationId, MyDatabaseId, GetUserId()) && !reltuple->relisshared) ||
-		pg_class_aclcheck(relid, GetUserId(), ACL_MAINTAIN) == ACLCHECK_OK ||
-		has_partition_ancestor_privs(relid, GetUserId(), ACL_MAINTAIN))
+		pg_class_aclcheck(relid, GetUserId(), ACL_MAINTAIN) == ACLCHECK_OK)
 		return true;
 
 	relname = NameStr(reltuple->relname);
diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h
@@ -99,7 +99,6 @@ extern void AtEOSubXact_on_commit_actions(bool isCommit,
 extern void RangeVarCallbackMaintainsTable(const RangeVar *relation,
 										   Oid relId, Oid oldRelId,
 										   void *arg);
-extern bool has_partition_ancestor_privs(Oid relid, Oid userid, AclMode acl);
 
 extern void RangeVarCallbackOwnsRelation(const RangeVar *relation,
 										 Oid relId, Oid oldRelId, void *arg);
diff --git a/src/test/isolation/expected/cluster-conflict-partition.out b/src/test/isolation/expected/cluster-conflict-partition.out
@@ -3,15 +3,15 @@ Parsed test spec with 2 sessions
 starting permutation: s1_begin s1_lock_parent s2_auth s2_cluster s1_commit s2_reset
 step s1_begin: BEGIN;
 step s1_lock_parent: LOCK cluster_part_tab IN SHARE UPDATE EXCLUSIVE MODE;
-step s2_auth: SET ROLE regress_cluster_part;
+step s2_auth: SET ROLE regress_cluster_part; SET client_min_messages = ERROR;
 step s2_cluster: CLUSTER cluster_part_tab USING cluster_part_ind; <waiting ...>
 step s1_commit: COMMIT;
 step s2_cluster: <... completed>
 step s2_reset: RESET ROLE;
 
 starting permutation: s1_begin s2_auth s1_lock_parent s2_cluster s1_commit s2_reset
 step s1_begin: BEGIN;
-step s2_auth: SET ROLE regress_cluster_part;
+step s2_auth: SET ROLE regress_cluster_part; SET client_min_messages = ERROR;
 step s1_lock_parent: LOCK cluster_part_tab IN SHARE UPDATE EXCLUSIVE MODE;
 step s2_cluster: CLUSTER cluster_part_tab USING cluster_part_ind; <waiting ...>
 step s1_commit: COMMIT;
@@ -21,17 +21,15 @@ step s2_reset: RESET ROLE;
 starting permutation: s1_begin s1_lock_child s2_auth s2_cluster s1_commit s2_reset
 step s1_begin: BEGIN;
 step s1_lock_child: LOCK cluster_part_tab1 IN SHARE UPDATE EXCLUSIVE MODE;
-step s2_auth: SET ROLE regress_cluster_part;
-step s2_cluster: CLUSTER cluster_part_tab USING cluster_part_ind; <waiting ...>
+step s2_auth: SET ROLE regress_cluster_part; SET client_min_messages = ERROR;
+step s2_cluster: CLUSTER cluster_part_tab USING cluster_part_ind;
 step s1_commit: COMMIT;
-step s2_cluster: <... completed>
 step s2_reset: RESET ROLE;
 
 starting permutation: s1_begin s2_auth s1_lock_child s2_cluster s1_commit s2_reset
 step s1_begin: BEGIN;
-step s2_auth: SET ROLE regress_cluster_part;
+step s2_auth: SET ROLE regress_cluster_part; SET client_min_messages = ERROR;
 step s1_lock_child: LOCK cluster_part_tab1 IN SHARE UPDATE EXCLUSIVE MODE;
-step s2_cluster: CLUSTER cluster_part_tab USING cluster_part_ind; <waiting ...>
+step s2_cluster: CLUSTER cluster_part_tab USING cluster_part_ind;
 step s1_commit: COMMIT;
-step s2_cluster: <... completed>
 step s2_reset: RESET ROLE;
diff --git a/src/test/isolation/specs/cluster-conflict-partition.spec b/src/test/isolation/specs/cluster-conflict-partition.spec
@@ -23,12 +23,15 @@ step s1_lock_child     { LOCK cluster_part_tab1 IN SHARE UPDATE EXCLUSIVE MODE;
 step s1_commit         { COMMIT; }
 
 session s2
-step s2_auth           { SET ROLE regress_cluster_part; }
+step s2_auth           { SET ROLE regress_cluster_part; SET client_min_messages = ERROR; }
 step s2_cluster        { CLUSTER cluster_part_tab USING cluster_part_ind; }
 step s2_reset          { RESET ROLE; }
 
-# CLUSTER waits if locked, passes for all cases.
+# CLUSTER on the parent waits if locked, passes for all cases.
 permutation s1_begin s1_lock_parent s2_auth s2_cluster s1_commit s2_reset
 permutation s1_begin s2_auth s1_lock_parent s2_cluster s1_commit s2_reset
+
+# When taking a lock on a partition leaf, CLUSTER on the parent skips
+# the leaf, passes for all cases.
 permutation s1_begin s1_lock_child s2_auth s2_cluster s1_commit s2_reset
 permutation s1_begin s2_auth s1_lock_child s2_cluster s1_commit s2_reset
diff --git a/src/test/regress/expected/cluster.out b/src/test/regress/expected/cluster.out
@@ -502,20 +502,25 @@ CREATE TABLE ptnowner1 PARTITION OF ptnowner FOR VALUES IN (1);
 CREATE ROLE regress_ptnowner;
 CREATE TABLE ptnowner2 PARTITION OF ptnowner FOR VALUES IN (2);
 ALTER TABLE ptnowner1 OWNER TO regress_ptnowner;
+SET SESSION AUTHORIZATION regress_ptnowner;
+CLUSTER ptnowner USING ptnowner_i_idx;
+ERROR:  permission denied for table ptnowner
+RESET SESSION AUTHORIZATION;
 ALTER TABLE ptnowner OWNER TO regress_ptnowner;
 CREATE TEMP TABLE ptnowner_oldnodes AS
   SELECT oid, relname, relfilenode FROM pg_partition_tree('ptnowner') AS tree
   JOIN pg_class AS c ON c.oid=tree.relid;
 SET SESSION AUTHORIZATION regress_ptnowner;
 CLUSTER ptnowner USING ptnowner_i_idx;
+WARNING:  permission denied to cluster "ptnowner2", skipping it
 RESET SESSION AUTHORIZATION;
 SELECT a.relname, a.relfilenode=b.relfilenode FROM pg_class a
   JOIN ptnowner_oldnodes b USING (oid) ORDER BY a.relname COLLATE "C";
   relname  | ?column? 
 -----------+----------
  ptnowner  | t
  ptnowner1 | f
- ptnowner2 | f
+ ptnowner2 | t
 (3 rows)
 
 DROP TABLE ptnowner;
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
@@ -2831,9 +2831,9 @@ RESET ROLE;
 GRANT USAGE ON SCHEMA pg_toast TO regress_reindexuser;
 SET SESSION ROLE regress_reindexuser;
 REINDEX TABLE pg_toast.pg_toast_1260;
-ERROR:  must be owner of table pg_toast_1260
+ERROR:  permission denied for table pg_toast_1260
 REINDEX INDEX pg_toast.pg_toast_1260_index;
-ERROR:  must be owner of index pg_toast_1260_index
+ERROR:  permission denied for index pg_toast_1260_index
 -- Clean up
 RESET ROLE;
 REVOKE USAGE ON SCHEMA pg_toast FROM regress_reindexuser;
diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
@@ -2928,13 +2928,13 @@ WARNING:  permission denied to analyze "maintain_test", skipping it
 VACUUM (ANALYZE) maintain_test;
 WARNING:  permission denied to vacuum "maintain_test", skipping it
 CLUSTER maintain_test USING maintain_test_a_idx;
-ERROR:  must be owner of table maintain_test
+ERROR:  permission denied for table maintain_test
 REFRESH MATERIALIZED VIEW refresh_test;
-ERROR:  must be owner of table refresh_test
+ERROR:  permission denied for table refresh_test
 REINDEX TABLE maintain_test;
-ERROR:  must be owner of table maintain_test
+ERROR:  permission denied for table maintain_test
 REINDEX INDEX maintain_test_a_idx;
-ERROR:  must be owner of index maintain_test_a_idx
+ERROR:  permission denied for index maintain_test_a_idx
 REINDEX SCHEMA reindex_test;
 ERROR:  must be owner of schema reindex_test
 RESET ROLE;
diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out
@@ -442,14 +442,20 @@ ALTER TABLE vacowned_parted OWNER TO regress_vacuum;
 ALTER TABLE vacowned_part1 OWNER TO regress_vacuum;
 SET ROLE regress_vacuum;
 VACUUM vacowned_parted;
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 VACUUM vacowned_part1;
 VACUUM vacowned_part2;
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 ANALYZE vacowned_parted;
+WARNING:  permission denied to analyze "vacowned_part2", skipping it
 ANALYZE vacowned_part1;
 ANALYZE vacowned_part2;
+WARNING:  permission denied to analyze "vacowned_part2", skipping it
 VACUUM (ANALYZE) vacowned_parted;
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 VACUUM (ANALYZE) vacowned_part1;
 VACUUM (ANALYZE) vacowned_part2;
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 RESET ROLE;
 -- Only one partition owned by other user.
 ALTER TABLE vacowned_parted OWNER TO CURRENT_USER;
@@ -478,14 +484,26 @@ ALTER TABLE vacowned_parted OWNER TO regress_vacuum;
 ALTER TABLE vacowned_part1 OWNER TO CURRENT_USER;
 SET ROLE regress_vacuum;
 VACUUM vacowned_parted;
+WARNING:  permission denied to vacuum "vacowned_part1", skipping it
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 VACUUM vacowned_part1;
+WARNING:  permission denied to vacuum "vacowned_part1", skipping it
 VACUUM vacowned_part2;
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 ANALYZE vacowned_parted;
+WARNING:  permission denied to analyze "vacowned_part1", skipping it
+WARNING:  permission denied to analyze "vacowned_part2", skipping it
 ANALYZE vacowned_part1;
+WARNING:  permission denied to analyze "vacowned_part1", skipping it
 ANALYZE vacowned_part2;
+WARNING:  permission denied to analyze "vacowned_part2", skipping it
 VACUUM (ANALYZE) vacowned_parted;
+WARNING:  permission denied to vacuum "vacowned_part1", skipping it
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 VACUUM (ANALYZE) vacowned_part1;
+WARNING:  permission denied to vacuum "vacowned_part1", skipping it
 VACUUM (ANALYZE) vacowned_part2;
+WARNING:  permission denied to vacuum "vacowned_part2", skipping it
 RESET ROLE;
 DROP TABLE vacowned;
 DROP TABLE vacowned_parted;
diff --git a/src/test/regress/sql/cluster.sql b/src/test/regress/sql/cluster.sql
