From edcda9bb4c4500b75bb4a16c7c59834398ca2906 Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Mon, 11 Nov 2024 09:00:00 -0600 Subject: [PATCH] Ensure cached plans are correctly marked as dependent on role. If a CTE, subquery, sublink, security invoker view, or coercion projection references a table with row-level security policies, 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. Reported-by: Wolfgang Walther Reviewed-by: Noah Misch Security: CVE-2024-10976 Backpatch-through: 12 --- src/backend/executor/functions.c | 6 ++ src/backend/rewrite/rewriteHandler.c | 67 +++++++++++++-- src/test/regress/expected/rowsecurity.out | 100 ++++++++++++++++++++++ src/test/regress/sql/rowsecurity.sql | 58 +++++++++++++ src/tools/pgindent/typedefs.list | 1 + 5 files changed, 226 insertions(+), 6 deletions(-) diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c index 692854e2b3e..39880663307 100644 --- a/src/backend/executor/functions.c +++ b/src/backend/executor/functions.c @@ -1972,6 +1972,12 @@ tlist_coercion_finished: rtr->rtindex = 1; newquery->jointree = makeFromExpr(list_make1(rtr), NULL); + /* + * Make sure the new query is marked as having row security if the + * original one does. + */ + newquery->hasRowSecurity = parse->hasRowSecurity; + /* Replace original query in the correct element of the query list */ lfirst(parse_cell) = newquery; } diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c index 6d59a2bb8dc..063afd4933e 100644 --- a/src/backend/rewrite/rewriteHandler.c +++ b/src/backend/rewrite/rewriteHandler.c @@ -58,6 +58,12 @@ typedef struct acquireLocksOnSubLinks_context bool for_execute; /* AcquireRewriteLocks' forExecute param */ } acquireLocksOnSubLinks_context; +typedef struct fireRIRonSubLink_context +{ + List *activeRIRs; + bool hasRowSecurity; +} fireRIRonSubLink_context; + static bool acquireLocksOnSubLinks(Node *node, acquireLocksOnSubLinks_context *context); static Query *rewriteRuleAction(Query *parsetree, @@ -1839,6 +1845,12 @@ ApplyRetrieveRule(Query *parsetree, */ rule_action = fireRIRrules(rule_action, activeRIRs); + /* + * Make sure the query is marked as having row security if the view query + * does. + */ + parsetree->hasRowSecurity |= rule_action->hasRowSecurity; + /* * Now, plug the view query in as a subselect, converting the relation's * original RTE to a subquery RTE. @@ -1952,7 +1964,7 @@ markQueryForLocking(Query *qry, Node *jtnode, * the SubLink's subselect link with the possibly-rewritten subquery. */ static bool -fireRIRonSubLink(Node *node, List *activeRIRs) +fireRIRonSubLink(Node *node, fireRIRonSubLink_context *context) { if (node == NULL) return false; @@ -1962,7 +1974,13 @@ fireRIRonSubLink(Node *node, List *activeRIRs) /* Do what we came for */ sub->subselect = (Node *) fireRIRrules((Query *) sub->subselect, - activeRIRs); + context->activeRIRs); + + /* + * Remember if any of the sublinks have row security. + */ + context->hasRowSecurity |= ((Query *) sub->subselect)->hasRowSecurity; + /* Fall through to process lefthand args of SubLink */ } @@ -1971,7 +1989,7 @@ fireRIRonSubLink(Node *node, List *activeRIRs) * subselects of subselects for us. */ return expression_tree_walker(node, fireRIRonSubLink, - (void *) activeRIRs); + (void *) context); } @@ -2032,6 +2050,13 @@ fireRIRrules(Query *parsetree, List *activeRIRs) if (rte->rtekind == RTE_SUBQUERY) { rte->subquery = fireRIRrules(rte->subquery, activeRIRs); + + /* + * While we are here, make sure the query is marked as having row + * security if any of its subqueries do. + */ + parsetree->hasRowSecurity |= rte->subquery->hasRowSecurity; + continue; } @@ -2145,6 +2170,12 @@ fireRIRrules(Query *parsetree, List *activeRIRs) cte->ctequery = (Node *) fireRIRrules((Query *) cte->ctequery, activeRIRs); + + /* + * While we are here, make sure the query is marked as having row + * security if any of its CTEs do. + */ + parsetree->hasRowSecurity |= ((Query *) cte->ctequery)->hasRowSecurity; } /* @@ -2152,9 +2183,22 @@ fireRIRrules(Query *parsetree, List *activeRIRs) * the rtable and cteList. */ if (parsetree->hasSubLinks) - query_tree_walker(parsetree, fireRIRonSubLink, (void *) activeRIRs, + { + fireRIRonSubLink_context context; + + context.activeRIRs = activeRIRs; + context.hasRowSecurity = false; + + query_tree_walker(parsetree, fireRIRonSubLink, (void *) &context, QTW_IGNORE_RC_SUBQUERIES); + /* + * Make sure the query is marked as having row security if any of its + * sublinks do. + */ + parsetree->hasRowSecurity |= context.hasRowSecurity; + } + /* * Apply any row-level security policies. We do this last because it * requires special recursion detection if the new quals have sublink @@ -2193,6 +2237,7 @@ fireRIRrules(Query *parsetree, List *activeRIRs) if (hasSubLinks) { acquireLocksOnSubLinks_context context; + fireRIRonSubLink_context fire_context; /* * Recursively process the new quals, checking for infinite @@ -2223,11 +2268,21 @@ fireRIRrules(Query *parsetree, List *activeRIRs) * Now that we have the locks on anything added by * get_row_security_policies, fire any RIR rules for them. */ + fire_context.activeRIRs = activeRIRs; + fire_context.hasRowSecurity = false; + expression_tree_walker((Node *) securityQuals, - fireRIRonSubLink, (void *) activeRIRs); + fireRIRonSubLink, (void *) &fire_context); expression_tree_walker((Node *) withCheckOptions, - fireRIRonSubLink, (void *) activeRIRs); + fireRIRonSubLink, (void *) &fire_context); + + /* + * We can ignore the value of fire_context.hasRowSecurity + * since we only reach this code in cases where hasRowSecurity + * is already true. + */ + Assert(hasRowSecurity); activeRIRs = list_delete_last(activeRIRs); } diff --git a/src/test/regress/expected/rowsecurity.out b/src/test/regress/expected/rowsecurity.out index 319190855bd..51bba175ec0 100644 --- a/src/test/regress/expected/rowsecurity.out +++ b/src/test/regress/expected/rowsecurity.out @@ -4554,8 +4554,108 @@ execute q; --------------+--- (0 rows) +-- make sure RLS dependencies in CTEs are handled +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ with cte as (select * from rls_t) select * from cte $$; +prepare r as select current_user, * from rls_f(); +set role regress_rls_alice; +execute r; + current_user | c +-------------------+------------------ + regress_rls_alice | invisible to bob +(1 row) + +set role regress_rls_bob; +execute r; + current_user | c +--------------+--- +(0 rows) + +-- make sure RLS dependencies in subqueries are handled +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select * from (select * from rls_t) _ $$; +prepare s as select current_user, * from rls_f(); +set role regress_rls_alice; +execute s; + current_user | c +-------------------+------------------ + regress_rls_alice | invisible to bob +(1 row) + +set role regress_rls_bob; +execute s; + current_user | c +--------------+--- +(0 rows) + +-- make sure RLS dependencies in sublinks are handled +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select exists(select * from rls_t)::text $$; +prepare t as select current_user, * from rls_f(); +set role regress_rls_alice; +execute t; + current_user | c +-------------------+------ + regress_rls_alice | true +(1 row) + +set role regress_rls_bob; +execute t; + current_user | c +-----------------+------- + regress_rls_bob | false +(1 row) + +-- make sure RLS dependencies are handled when coercion projections are inserted +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select * from (select array_agg(c) as cs from rls_t) _ group by cs $$; +prepare u as select current_user, * from rls_f(); +set role regress_rls_alice; +execute u; + current_user | c +-------------------+---------------------- + regress_rls_alice | {"invisible to bob"} +(1 row) + +set role regress_rls_bob; +execute u; + current_user | c +-----------------+--- + regress_rls_bob | +(1 row) + +-- make sure RLS dependencies in security invoker views are handled +reset role; +create view rls_v with (security_invoker) as select * from rls_t; +grant select on rls_v to regress_rls_alice, regress_rls_bob; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select * from rls_v $$; +prepare v as select current_user, * from rls_f(); +set role regress_rls_alice; +execute v; + current_user | c +-------------------+------------------ + regress_rls_alice | invisible to bob +(1 row) + +set role regress_rls_bob; +execute v; + current_user | c +--------------+--- +(0 rows) + RESET ROLE; DROP FUNCTION rls_f(); +DROP VIEW rls_v; DROP TABLE rls_t; -- -- Clean up objects diff --git a/src/test/regress/sql/rowsecurity.sql b/src/test/regress/sql/rowsecurity.sql index 3011d71b12b..eab7d99003e 100644 --- a/src/test/regress/sql/rowsecurity.sql +++ b/src/test/regress/sql/rowsecurity.sql @@ -2217,8 +2217,66 @@ execute q; set role regress_rls_bob; execute q; +-- make sure RLS dependencies in CTEs are handled +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ with cte as (select * from rls_t) select * from cte $$; +prepare r as select current_user, * from rls_f(); +set role regress_rls_alice; +execute r; +set role regress_rls_bob; +execute r; + +-- make sure RLS dependencies in subqueries are handled +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select * from (select * from rls_t) _ $$; +prepare s as select current_user, * from rls_f(); +set role regress_rls_alice; +execute s; +set role regress_rls_bob; +execute s; + +-- make sure RLS dependencies in sublinks are handled +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select exists(select * from rls_t)::text $$; +prepare t as select current_user, * from rls_f(); +set role regress_rls_alice; +execute t; +set role regress_rls_bob; +execute t; + +-- make sure RLS dependencies are handled when coercion projections are inserted +reset role; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select * from (select array_agg(c) as cs from rls_t) _ group by cs $$; +prepare u as select current_user, * from rls_f(); +set role regress_rls_alice; +execute u; +set role regress_rls_bob; +execute u; + +-- make sure RLS dependencies in security invoker views are handled +reset role; +create view rls_v with (security_invoker) as select * from rls_t; +grant select on rls_v to regress_rls_alice, regress_rls_bob; +create or replace function rls_f() returns setof rls_t + stable language sql + as $$ select * from rls_v $$; +prepare v as select current_user, * from rls_f(); +set role regress_rls_alice; +execute v; +set role regress_rls_bob; +execute v; + RESET ROLE; DROP FUNCTION rls_f(); +DROP VIEW rls_v; DROP TABLE rls_t; -- diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index 5628b3f09f4..c398d984bbe 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -3451,6 +3451,7 @@ fill_string_relopt finalize_primnode_context find_dependent_phvs_context find_expr_references_context +fireRIRonSubLink_context fix_join_expr_context fix_scan_expr_context fix_upper_expr_context