Handle RLS dependencies in inlined set-returning functions properly.

If an SRF in the FROM clause references a table having row-level
security policies, and we inline that SRF into the calling query,
we neglected to mark the plan as potentially dependent on which
role is executing it.  This could lead to later executions in the
same session returning or hiding rows that should have been hidden
or returned instead.

Our thanks to Wolfgang Walther for reporting this problem.

Stephen Frost and Tom Lane

Security: CVE-2023-2455

diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index dc908eae43695d211e83387293866f213809bd0d..10843fb38008cac3e64fbe37efdc76f927afccc9 100644 (file)
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -5110,6 +5110,13 @@ inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
     */
    record_plan_function_dependency(root, func_oid);
 
+   /*
+    * We must also notice if the inserted query adds a dependency on the
+    * calling role due to RLS quals.
+    */
+   if (querytree->hasRowSecurity)
+       root->glob->dependsOnRole = true;
+
    return querytree;
 
    /* Here if func is not inlinable: release temp memory and return NULL */

diff --git a/src/test/regress/expected/rowsecurity.out b/src/test/regress/expected/rowsecurity.out
index 8ef52437fc24ba1fc64ce96da2657a55b8552104..a844aeb03e2ec4492d5163b0c266bb6201c79f05 100644 (file)
--- a/src/test/regress/expected/rowsecurity.out
+++ b/src/test/regress/expected/rowsecurity.out
@@ -4038,6 +4038,33 @@ SELECT * FROM rls_tbl;
 
 DROP TABLE rls_tbl;
 RESET SESSION AUTHORIZATION;
+-- CVE-2023-2455: inlining an SRF may introduce an RLS dependency
+create table rls_t (c text);
+insert into rls_t values ('invisible to bob');
+alter table rls_t enable row level security;
+grant select on rls_t to regress_rls_alice, regress_rls_bob;
+create policy p1 on rls_t for select to regress_rls_alice using (true);
+create policy p2 on rls_t for select to regress_rls_bob using (false);
+create function rls_f () returns setof rls_t
+  stable language sql
+  as $$ select * from rls_t $$;
+prepare q as select current_user, * from rls_f();
+set role regress_rls_alice;
+execute q;
+   current_user    |        c         
+-------------------+------------------
+ regress_rls_alice | invisible to bob
+(1 row)
+
+set role regress_rls_bob;
+execute q;
+ current_user | c 
+--------------+---
+(0 rows)
+
+RESET ROLE;
+DROP FUNCTION rls_f();
+DROP TABLE rls_t;
 --
 -- Clean up objects
 --

diff --git a/src/test/regress/sql/rowsecurity.sql b/src/test/regress/sql/rowsecurity.sql
index 8845bebe2f2eb593e98885bcc65070c539cbd4a6..6973cc4ed0413c43279a3ea18d53d6f44099f974 100644 (file)
--- a/src/test/regress/sql/rowsecurity.sql
+++ b/src/test/regress/sql/rowsecurity.sql
@@ -1873,6 +1873,26 @@ SELECT * FROM rls_tbl;
 DROP TABLE rls_tbl;
 RESET SESSION AUTHORIZATION;
 
+-- CVE-2023-2455: inlining an SRF may introduce an RLS dependency
+create table rls_t (c text);
+insert into rls_t values ('invisible to bob');
+alter table rls_t enable row level security;
+grant select on rls_t to regress_rls_alice, regress_rls_bob;
+create policy p1 on rls_t for select to regress_rls_alice using (true);
+create policy p2 on rls_t for select to regress_rls_bob using (false);
+create function rls_f () returns setof rls_t
+  stable language sql
+  as $$ select * from rls_t $$;
+prepare q as select current_user, * from rls_f();
+set role regress_rls_alice;
+execute q;
+set role regress_rls_bob;
+execute q;
+
+RESET ROLE;
+DROP FUNCTION rls_f();
+DROP TABLE rls_t;
+
 --
 -- Clean up objects
 --