postgresql: fix CVE-2023-2454 & CVE-2023-2455

fixed Below security CVE:
1)CVE-2023-2454 postgresql: schema_element defeats protective search_path changes.
2)CVE-2023-2455 postgresql: row security policies disregard user ID changes after inlining.

Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
This commit is contained in:
vkumbhar 2023-06-27 16:18:58 +05:30 committed by Armin Kuster
parent e5808a69cd
commit 5f94e67479
3 changed files with 355 additions and 0 deletions

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@ -0,0 +1,235 @@
From 23cb8eaeb97df350273cb8902e55842a955339c8 Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Mon, 8 May 2023 06:14:07 -0700
Subject: [PATCH] Replace last PushOverrideSearchPath() call with
set_config_option().
The two methods don't cooperate, so set_config_option("search_path",
...) has been ineffective under non-empty overrideStack. This defect
enabled an attacker having database-level CREATE privilege to execute
arbitrary code as the bootstrap superuser. While that particular attack
requires v13+ for the trusted extension attribute, other attacks are
feasible in all supported versions.
Standardize on the combination of NewGUCNestLevel() and
set_config_option("search_path", ...). It is newer than
PushOverrideSearchPath(), more-prevalent, and has no known
disadvantages. The "override" mechanism remains for now, for
compatibility with out-of-tree code. Users should update such code,
which likely suffers from the same sort of vulnerability closed here.
Back-patch to v11 (all supported versions).
Alexander Lakhin. Reported by Alexander Lakhin.
Security: CVE-2023-2454
Upstream-Status: Backport [https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=23cb8eaeb97df350273cb8902e55842a955339c8]
CVE: CVE-2023-2454
Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
---
src/backend/catalog/namespace.c | 4 +++
src/backend/commands/schemacmds.c | 37 ++++++++++++++------
src/test/regress/expected/namespace.out | 45 +++++++++++++++++++++++++
src/test/regress/sql/namespace.sql | 24 +++++++++++++
4 files changed, 100 insertions(+), 10 deletions(-)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 48a7058..74a0536 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3456,6 +3456,10 @@ OverrideSearchPathMatchesCurrent(OverrideSearchPath *path)
/*
* PushOverrideSearchPath - temporarily override the search path
*
+ * Do not use this function; almost any usage introduces a security
+ * vulnerability. It exists for the benefit of legacy code running in
+ * non-security-sensitive environments.
+ *
* We allow nested overrides, hence the push/pop terminology. The GUC
* search_path variable is ignored while an override is active.
*
diff --git a/src/backend/commands/schemacmds.c b/src/backend/commands/schemacmds.c
index 6bc4edc..27b1241 100644
--- a/src/backend/commands/schemacmds.c
+++ b/src/backend/commands/schemacmds.c
@@ -29,6 +29,7 @@
#include "commands/schemacmds.h"
#include "miscadmin.h"
#include "parser/parse_utilcmd.h"
+#include "parser/scansup.h"
#include "tcop/utility.h"
#include "utils/acl.h"
#include "utils/builtins.h"
@@ -53,14 +54,16 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
{
const char *schemaName = stmt->schemaname;
Oid namespaceId;
- OverrideSearchPath *overridePath;
List *parsetree_list;
ListCell *parsetree_item;
Oid owner_uid;
Oid saved_uid;
int save_sec_context;
+ int save_nestlevel;
+ char *nsp = namespace_search_path;
AclResult aclresult;
ObjectAddress address;
+ StringInfoData pathbuf;
GetUserIdAndSecContext(&saved_uid, &save_sec_context);
@@ -153,14 +156,26 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
CommandCounterIncrement();
/*
- * Temporarily make the new namespace be the front of the search path, as
- * well as the default creation target namespace. This will be undone at
- * the end of this routine, or upon error.
+ * Prepend the new schema to the current search path.
+ *
+ * We use the equivalent of a function SET option to allow the setting to
+ * persist for exactly the duration of the schema creation. guc.c also
+ * takes care of undoing the setting on error.
*/
- overridePath = GetOverrideSearchPath(CurrentMemoryContext);
- overridePath->schemas = lcons_oid(namespaceId, overridePath->schemas);
- /* XXX should we clear overridePath->useTemp? */
- PushOverrideSearchPath(overridePath);
+ save_nestlevel = NewGUCNestLevel();
+
+ initStringInfo(&pathbuf);
+ appendStringInfoString(&pathbuf, quote_identifier(schemaName));
+
+ while (scanner_isspace(*nsp))
+ nsp++;
+
+ if (*nsp != '\0')
+ appendStringInfo(&pathbuf, ", %s", nsp);
+
+ (void) set_config_option("search_path", pathbuf.data,
+ PGC_USERSET, PGC_S_SESSION,
+ GUC_ACTION_SAVE, true, 0, false);
/*
* Report the new schema to possibly interested event triggers. Note we
@@ -213,8 +228,10 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
CommandCounterIncrement();
}
- /* Reset search path to normal state */
- PopOverrideSearchPath();
+ /*
+ * Restore the GUC variable search_path we set above.
+ */
+ AtEOXact_GUC(true, save_nestlevel);
/* Reset current user and security context */
SetUserIdAndSecContext(saved_uid, save_sec_context);
diff --git a/src/test/regress/expected/namespace.out b/src/test/regress/expected/namespace.out
index 2564d1b..a62fd8d 100644
--- a/src/test/regress/expected/namespace.out
+++ b/src/test/regress/expected/namespace.out
@@ -1,6 +1,14 @@
--
-- Regression tests for schemas (namespaces)
--
+-- set the whitespace-only search_path to test that the
+-- GUC list syntax is preserved during a schema creation
+SELECT pg_catalog.set_config('search_path', ' ', false);
+ set_config
+------------
+
+(1 row)
+
CREATE SCHEMA test_ns_schema_1
CREATE UNIQUE INDEX abc_a_idx ON abc (a)
CREATE VIEW abc_view AS
@@ -9,6 +17,43 @@ CREATE SCHEMA test_ns_schema_1
a serial,
b int UNIQUE
);
+-- verify that the correct search_path restored on abort
+SET search_path to public;
+BEGIN;
+SET search_path to public, test_ns_schema_1;
+CREATE SCHEMA test_ns_schema_2
+ CREATE VIEW abc_view AS SELECT c FROM abc;
+ERROR: column "c" does not exist
+LINE 2: CREATE VIEW abc_view AS SELECT c FROM abc;
+ ^
+COMMIT;
+SHOW search_path;
+ search_path
+-------------
+ public
+(1 row)
+
+-- verify that the correct search_path preserved
+-- after creating the schema and on commit
+BEGIN;
+SET search_path to public, test_ns_schema_1;
+CREATE SCHEMA test_ns_schema_2
+ CREATE VIEW abc_view AS SELECT a FROM abc;
+SHOW search_path;
+ search_path
+--------------------------
+ public, test_ns_schema_1
+(1 row)
+
+COMMIT;
+SHOW search_path;
+ search_path
+--------------------------
+ public, test_ns_schema_1
+(1 row)
+
+DROP SCHEMA test_ns_schema_2 CASCADE;
+NOTICE: drop cascades to view test_ns_schema_2.abc_view
-- verify that the objects were created
SELECT COUNT(*) FROM pg_class WHERE relnamespace =
(SELECT oid FROM pg_namespace WHERE nspname = 'test_ns_schema_1');
diff --git a/src/test/regress/sql/namespace.sql b/src/test/regress/sql/namespace.sql
index 6b12c96..3474f5e 100644
--- a/src/test/regress/sql/namespace.sql
+++ b/src/test/regress/sql/namespace.sql
@@ -2,6 +2,10 @@
-- Regression tests for schemas (namespaces)
--
+-- set the whitespace-only search_path to test that the
+-- GUC list syntax is preserved during a schema creation
+SELECT pg_catalog.set_config('search_path', ' ', false);
+
CREATE SCHEMA test_ns_schema_1
CREATE UNIQUE INDEX abc_a_idx ON abc (a)
@@ -13,6 +17,26 @@ CREATE SCHEMA test_ns_schema_1
b int UNIQUE
);
+-- verify that the correct search_path restored on abort
+SET search_path to public;
+BEGIN;
+SET search_path to public, test_ns_schema_1;
+CREATE SCHEMA test_ns_schema_2
+ CREATE VIEW abc_view AS SELECT c FROM abc;
+COMMIT;
+SHOW search_path;
+
+-- verify that the correct search_path preserved
+-- after creating the schema and on commit
+BEGIN;
+SET search_path to public, test_ns_schema_1;
+CREATE SCHEMA test_ns_schema_2
+ CREATE VIEW abc_view AS SELECT a FROM abc;
+SHOW search_path;
+COMMIT;
+SHOW search_path;
+DROP SCHEMA test_ns_schema_2 CASCADE;
+
-- verify that the objects were created
SELECT COUNT(*) FROM pg_class WHERE relnamespace =
(SELECT oid FROM pg_namespace WHERE nspname = 'test_ns_schema_1');
--
2.25.1

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@ -0,0 +1,118 @@
From 473626cf00babd829eb15c36b51dfb358d32bc95 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 8 May 2023 10:12:45 -0400
Subject: [PATCH] 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
Upstream-Status: Backport [https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=473626cf00babd829eb15c36b51dfb358d32bc95]
CVE: CVE-2023-2455
Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
---
src/backend/optimizer/util/clauses.c | 7 ++++++
src/test/regress/expected/rowsecurity.out | 27 +++++++++++++++++++++++
src/test/regress/sql/rowsecurity.sql | 20 +++++++++++++++++
3 files changed, 54 insertions(+)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 946e232..b8e469f 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -5142,6 +5142,13 @@ 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 5116e23..26eecd0 100644
--- a/src/test/regress/expected/rowsecurity.out
+++ b/src/test/regress/expected/rowsecurity.out
@@ -4001,6 +4001,33 @@ 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 178eeb0..83d99e3 100644
--- a/src/test/regress/sql/rowsecurity.sql
+++ b/src/test/regress/sql/rowsecurity.sql
@@ -1839,6 +1839,26 @@ 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
--
--
2.25.1

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@ -10,6 +10,8 @@ SRC_URI += "\
file://CVE-2022-1552.patch \
file://CVE-2022-2625.patch \
file://CVE-2022-41862.patch \
file://CVE-2023-2454.patch \
file://CVE-2023-2455.patch \
"
SRC_URI[sha256sum] = "89fda2de33ed04a98548e43f3ee5f15b882be17505d631fe0dd1a540a2b56dce"