In REFRESH MATERIALIZED VIEW, set user ID before running user code.

It intended to, but did not, achieve this.  Adopt the new standard of
setting user ID just after locking the relation.  Back-patch to v10 (all
supported versions).

Reviewed by Simon Riggs.  Reported by Alvaro Herrera.

Security: CVE-2022-1552

diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index 9ab248d25e0889cc5712a76d3a548365b2fe0b8e..52534f182745e2b29038ab4ce56533aab6df3f77 100644 (file)
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -167,6 +167,17 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
                                          lockmode, 0,
                                          RangeVarCallbackOwnsTable, NULL);
    matviewRel = table_open(matviewOid, NoLock);
+   relowner = matviewRel->rd_rel->relowner;
+
+   /*
+    * Switch to the owner's userid, so that any functions are run as that
+    * user.  Also lock down security-restricted operations and arrange to
+    * make GUC variable changes local to this command.
+    */
+   GetUserIdAndSecContext(&save_userid, &save_sec_context);
+   SetUserIdAndSecContext(relowner,
+                          save_sec_context | SECURITY_RESTRICTED_OPERATION);
+   save_nestlevel = NewGUCNestLevel();
 
    /* Make sure it is a materialized view. */
    if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW)
@@ -269,19 +280,6 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
     */
    SetMatViewPopulatedState(matviewRel, !stmt->skipData);
 
-   relowner = matviewRel->rd_rel->relowner;
-
-   /*
-    * Switch to the owner's userid, so that any functions are run as that
-    * user.  Also arrange to make GUC variable changes local to this command.
-    * Don't lock it down too tight to create a temporary table just yet.  We
-    * will switch modes when we are about to execute user code.
-    */
-   GetUserIdAndSecContext(&save_userid, &save_sec_context);
-   SetUserIdAndSecContext(relowner,
-                          save_sec_context | SECURITY_LOCAL_USERID_CHANGE);
-   save_nestlevel = NewGUCNestLevel();
-
    /* Concurrent refresh builds new data in temp tablespace, and does diff. */
    if (concurrent)
    {
@@ -305,12 +303,6 @@ ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString,
    LockRelationOid(OIDNewHeap, AccessExclusiveLock);
    dest = CreateTransientRelDestReceiver(OIDNewHeap);
 
-   /*
-    * Now lock down security-restricted operations.
-    */
-   SetUserIdAndSecContext(relowner,
-                          save_sec_context | SECURITY_RESTRICTED_OPERATION);
-
    /* Generate the data, if wanted. */
    if (!stmt->skipData)
        processed = refresh_matview_datafill(dest, dataQuery, queryString);

diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
index 4a3709e3151481a348355d60acafde635917a553..03df567d50f6699f32ff96ab5409609b3f288000 100644 (file)
--- a/src/test/regress/expected/privileges.out
+++ b/src/test/regress/expected/privileges.out
@@ -1684,6 +1684,22 @@ CONTEXT:  SQL function "unwanted_grant" statement 1
 SQL statement "SELECT unwanted_grant()"
 PL/pgSQL function sro_trojan() line 1 at PERFORM
 SQL function "mv_action" statement 1
+-- REFRESH MATERIALIZED VIEW CONCURRENTLY use of eval_const_expressions()
+SET SESSION AUTHORIZATION regress_sro_user;
+CREATE FUNCTION unwanted_grant_nofail(int) RETURNS int
+   IMMUTABLE LANGUAGE plpgsql AS $$
+BEGIN
+   PERFORM unwanted_grant();
+   RAISE WARNING 'owned';
+   RETURN 1;
+EXCEPTION WHEN OTHERS THEN
+   RETURN 2;
+END$$;
+CREATE MATERIALIZED VIEW sro_index_mv AS SELECT 1 AS c;
+CREATE UNIQUE INDEX ON sro_index_mv (c) WHERE unwanted_grant_nofail(1) > 0;
+\c -
+REFRESH MATERIALIZED VIEW CONCURRENTLY sro_index_mv;
+REFRESH MATERIALIZED VIEW sro_index_mv;
 DROP OWNED BY regress_sro_user;
 DROP ROLE regress_sro_user;
 -- Admin options

diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
index 55df7f3b32e55ce3e0b9a77af941ed935ab44041..2a6ba38e523729444b31ae648e29af21065e5a30 100644 (file)
--- a/src/test/regress/sql/privileges.sql
+++ b/src/test/regress/sql/privileges.sql
@@ -1116,6 +1116,23 @@ REFRESH MATERIALIZED VIEW sro_mv;
 REFRESH MATERIALIZED VIEW sro_mv;
 BEGIN; SET CONSTRAINTS ALL IMMEDIATE; REFRESH MATERIALIZED VIEW sro_mv; COMMIT;
 
+-- REFRESH MATERIALIZED VIEW CONCURRENTLY use of eval_const_expressions()
+SET SESSION AUTHORIZATION regress_sro_user;
+CREATE FUNCTION unwanted_grant_nofail(int) RETURNS int
+   IMMUTABLE LANGUAGE plpgsql AS $$
+BEGIN
+   PERFORM unwanted_grant();
+   RAISE WARNING 'owned';
+   RETURN 1;
+EXCEPTION WHEN OTHERS THEN
+   RETURN 2;
+END$$;
+CREATE MATERIALIZED VIEW sro_index_mv AS SELECT 1 AS c;
+CREATE UNIQUE INDEX ON sro_index_mv (c) WHERE unwanted_grant_nofail(1) > 0;
+\c -
+REFRESH MATERIALIZED VIEW CONCURRENTLY sro_index_mv;
+REFRESH MATERIALIZED VIEW sro_index_mv;
+
 DROP OWNED BY regress_sro_user;
 DROP ROLE regress_sro_user;