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 a9c7bc342eccec6964a98796ee6f92ac3a578a73..11269fee3ed65fbe7ca225ae6e41b5d3fb89b0c6 100644 (file)
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -5205,6 +5205,13 @@ 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 38f53ed4868b3cadc6f645c729cd4c0264f661fc..e27834642082a19d1cba7634b22f2e540a4abc36 100644 (file)
--- a/src/test/regress/expected/rowsecurity.out
+++ b/src/test/regress/expected/rowsecurity.out
@@ -4427,6 +4427,33 @@ 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 0fd0cded7db44b347b2232b583236dfa728f7acf..3d664538a69653e2a8a0fa3611c001ef25753eb5 100644 (file)
--- a/src/test/regress/sql/rowsecurity.sql
+++ b/src/test/regress/sql/rowsecurity.sql
@@ -2127,6 +2127,26 @@ 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
 --