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 bf3a7cae60a0ff521e4ef4d2f433983aa5035bee..f2216f590e3f3c6ed774b2f81de522a384ea8be2 100644 (file)
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -5143,6 +5143,13 @@ 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 fb86c13b1d6aa898f70f049aa7b834f56defeda1..1fec044c4975a6cd3a713573d8b2f42bbb6315ac 100644 (file)
--- a/src/test/regress/expected/rowsecurity.out
+++ b/src/test/regress/expected/rowsecurity.out
@@ -4455,6 +4455,33 @@ 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 e0420d437871b617fe71b543287d925b488a073c..faad37ec81bfcd38c553094342520ce7fcd8e025 100644 (file)
--- a/src/test/regress/sql/rowsecurity.sql
+++ b/src/test/regress/sql/rowsecurity.sql
@@ -2151,6 +2151,26 @@ 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
 --