Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit681d9e4

Browse files
committed
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 defectenabled an attacker having database-level CREATE privilege to executearbitrary code as the bootstrap superuser. While that particular attackrequires v13+ for the trusted extension attribute, other attacks arefeasible in all supported versions.Standardize on the combination of NewGUCNestLevel() andset_config_option("search_path", ...). It is newer thanPushOverrideSearchPath(), more-prevalent, and has no knowndisadvantages. The "override" mechanism remains for now, forcompatibility 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
1 parentb8c3f6d commit681d9e4

File tree

7 files changed

+165
-11
lines changed

7 files changed

+165
-11
lines changed

‎contrib/seg/Makefile

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,7 @@ PGFILEDESC = "seg - line segment data type"
1414

1515
HEADERS = segdata.h
1616

17-
REGRESS = seg
17+
REGRESS =securityseg
1818

1919
EXTRA_CLEAN = y.tab.c y.tab.h
2020

‎contrib/seg/expected/security.out

Lines changed: 32 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,32 @@
1+
--
2+
-- Test extension script protection against search path overriding
3+
--
4+
CREATE ROLE regress_seg_role;
5+
SELECT current_database() AS datname \gset
6+
GRANT CREATE ON DATABASE :"datname" TO regress_seg_role;
7+
SET ROLE regress_seg_role;
8+
CREATE SCHEMA regress_seg_schema;
9+
CREATE FUNCTION regress_seg_schema.exfun(i int) RETURNS int AS $$
10+
BEGIN
11+
CREATE EXTENSION seg VERSION '1.2';
12+
13+
CREATE FUNCTION regress_seg_schema.compare(oid, regclass) RETURNS boolean AS
14+
'BEGIN RAISE EXCEPTION ''overloaded compare() called by %'', current_user; END;' LANGUAGE plpgsql;
15+
16+
CREATE OPERATOR = (LEFTARG = oid, RIGHTARG = regclass, PROCEDURE = regress_seg_schema.compare);
17+
18+
ALTER EXTENSION seg UPDATE TO '1.3';
19+
20+
RETURN i;
21+
END; $$ LANGUAGE plpgsql;
22+
CREATE SCHEMA test_schema
23+
CREATE TABLE t(i int) PARTITION BY RANGE (i)
24+
CREATE TABLE p1 PARTITION OF t FOR VALUES FROM (1) TO (regress_seg_schema.exfun(2));
25+
DROP SCHEMA test_schema CASCADE;
26+
NOTICE: drop cascades to 3 other objects
27+
DETAIL: drop cascades to table test_schema.t
28+
drop cascades to extension seg
29+
drop cascades to operator test_schema.=(oid,regclass)
30+
RESET ROLE;
31+
DROP OWNED BY regress_seg_role;
32+
DROP ROLE regress_seg_role;

‎contrib/seg/sql/security.sql

Lines changed: 32 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,32 @@
1+
--
2+
-- Test extension script protection against search path overriding
3+
--
4+
5+
CREATE ROLE regress_seg_role;
6+
SELECT current_database()AS datname \gset
7+
GRANT CREATEON DATABASE :"datname" TO regress_seg_role;
8+
SET ROLE regress_seg_role;
9+
CREATESCHEMAregress_seg_schema;
10+
11+
CREATEFUNCTIONregress_seg_schema.exfun(iint) RETURNSintAS $$
12+
BEGIN
13+
CREATE EXTENSION seg VERSION'1.2';
14+
15+
CREATEFUNCTIONregress_seg_schema.compare(oid, regclass) RETURNSbooleanAS
16+
'BEGIN RAISE EXCEPTION''overloaded compare() called by %'', current_user; END;' LANGUAGE plpgsql;
17+
18+
CREATE OPERATOR= (LEFTARG=oid, RIGHTARG= regclass, PROCEDURE=regress_seg_schema.compare);
19+
20+
ALTER EXTENSION segUPDATE TO'1.3';
21+
22+
RETURN i;
23+
END; $$ LANGUAGE plpgsql;
24+
25+
CREATESCHEMAtest_schema
26+
CREATETABLEt(iint) PARTITION BY RANGE (i)
27+
CREATETABLEp1 PARTITION OF t FORVALUESFROM (1) TO (regress_seg_schema.exfun(2));
28+
29+
DROPSCHEMA test_schema CASCADE;
30+
RESET ROLE;
31+
DROP OWNED BY regress_seg_role;
32+
DROP ROLE regress_seg_role;

‎src/backend/catalog/namespace.c

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -3515,6 +3515,10 @@ OverrideSearchPathMatchesCurrent(OverrideSearchPath *path)
35153515
/*
35163516
* PushOverrideSearchPath - temporarily override the search path
35173517
*
3518+
* Do not use this function; almost any usage introduces a security
3519+
* vulnerability. It exists for the benefit of legacy code running in
3520+
* non-security-sensitive environments.
3521+
*
35183522
* We allow nested overrides, hence the push/pop terminology. The GUC
35193523
* search_path variable is ignored while an override is active.
35203524
*

‎src/backend/commands/schemacmds.c

Lines changed: 27 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -30,6 +30,7 @@
3030
#include"commands/schemacmds.h"
3131
#include"miscadmin.h"
3232
#include"parser/parse_utilcmd.h"
33+
#include"parser/scansup.h"
3334
#include"tcop/utility.h"
3435
#include"utils/acl.h"
3536
#include"utils/builtins.h"
@@ -53,14 +54,16 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
5354
{
5455
constchar*schemaName=stmt->schemaname;
5556
OidnamespaceId;
56-
OverrideSearchPath*overridePath;
5757
List*parsetree_list;
5858
ListCell*parsetree_item;
5959
Oidowner_uid;
6060
Oidsaved_uid;
6161
intsave_sec_context;
62+
intsave_nestlevel;
63+
char*nsp=namespace_search_path;
6264
AclResultaclresult;
6365
ObjectAddressaddress;
66+
StringInfoDatapathbuf;
6467

6568
GetUserIdAndSecContext(&saved_uid,&save_sec_context);
6669

@@ -153,14 +156,26 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
153156
CommandCounterIncrement();
154157

155158
/*
156-
* Temporarily make the new namespace be the front of the search path, as
157-
* well as the default creation target namespace. This will be undone at
158-
* the end of this routine, or upon error.
159+
* Prepend the new schema to the current search path.
160+
*
161+
* We use the equivalent of a function SET option to allow the setting to
162+
* persist for exactly the duration of the schema creation. guc.c also
163+
* takes care of undoing the setting on error.
159164
*/
160-
overridePath=GetOverrideSearchPath(CurrentMemoryContext);
161-
overridePath->schemas=lcons_oid(namespaceId,overridePath->schemas);
162-
/* XXX should we clear overridePath->useTemp? */
163-
PushOverrideSearchPath(overridePath);
165+
save_nestlevel=NewGUCNestLevel();
166+
167+
initStringInfo(&pathbuf);
168+
appendStringInfoString(&pathbuf,quote_identifier(schemaName));
169+
170+
while (scanner_isspace(*nsp))
171+
nsp++;
172+
173+
if (*nsp!='\0')
174+
appendStringInfo(&pathbuf,", %s",nsp);
175+
176+
(void)set_config_option("search_path",pathbuf.data,
177+
PGC_USERSET,PGC_S_SESSION,
178+
GUC_ACTION_SAVE, true,0, false);
164179

165180
/*
166181
* Report the new schema to possibly interested event triggers. Note we
@@ -215,8 +230,10 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString,
215230
CommandCounterIncrement();
216231
}
217232

218-
/* Reset search path to normal state */
219-
PopOverrideSearchPath();
233+
/*
234+
* Restore the GUC variable search_path we set above.
235+
*/
236+
AtEOXact_GUC(true,save_nestlevel);
220237

221238
/* Reset current user and security context */
222239
SetUserIdAndSecContext(saved_uid,save_sec_context);

‎src/test/regress/expected/namespace.out

Lines changed: 45 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,14 @@
11
--
22
-- Regression tests for schemas (namespaces)
33
--
4+
-- set the whitespace-only search_path to test that the
5+
-- GUC list syntax is preserved during a schema creation
6+
SELECT pg_catalog.set_config('search_path', ' ', false);
7+
set_config
8+
------------
9+
10+
(1 row)
11+
412
CREATE SCHEMA test_ns_schema_1
513
CREATE UNIQUE INDEX abc_a_idx ON abc (a)
614
CREATE VIEW abc_view AS
@@ -9,6 +17,43 @@ CREATE SCHEMA test_ns_schema_1
917
a serial,
1018
b int UNIQUE
1119
);
20+
-- verify that the correct search_path restored on abort
21+
SET search_path to public;
22+
BEGIN;
23+
SET search_path to public, test_ns_schema_1;
24+
CREATE SCHEMA test_ns_schema_2
25+
CREATE VIEW abc_view AS SELECT c FROM abc;
26+
ERROR: column "c" does not exist
27+
LINE 2: CREATE VIEW abc_view AS SELECT c FROM abc;
28+
^
29+
COMMIT;
30+
SHOW search_path;
31+
search_path
32+
-------------
33+
public
34+
(1 row)
35+
36+
-- verify that the correct search_path preserved
37+
-- after creating the schema and on commit
38+
BEGIN;
39+
SET search_path to public, test_ns_schema_1;
40+
CREATE SCHEMA test_ns_schema_2
41+
CREATE VIEW abc_view AS SELECT a FROM abc;
42+
SHOW search_path;
43+
search_path
44+
--------------------------
45+
public, test_ns_schema_1
46+
(1 row)
47+
48+
COMMIT;
49+
SHOW search_path;
50+
search_path
51+
--------------------------
52+
public, test_ns_schema_1
53+
(1 row)
54+
55+
DROP SCHEMA test_ns_schema_2 CASCADE;
56+
NOTICE: drop cascades to view test_ns_schema_2.abc_view
1257
-- verify that the objects were created
1358
SELECT COUNT(*) FROM pg_class WHERE relnamespace =
1459
(SELECT oid FROM pg_namespace WHERE nspname = 'test_ns_schema_1');

‎src/test/regress/sql/namespace.sql

Lines changed: 24 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2,6 +2,10 @@
22
-- Regression tests for schemas (namespaces)
33
--
44

5+
-- set the whitespace-only search_path to test that the
6+
-- GUC list syntax is preserved during a schema creation
7+
SELECTpg_catalog.set_config('search_path','', false);
8+
59
CREATESCHEMAtest_ns_schema_1
610
CREATEUNIQUE INDEXabc_a_idxON abc (a)
711

@@ -13,6 +17,26 @@ CREATE SCHEMA test_ns_schema_1
1317
bint UNIQUE
1418
);
1519

20+
-- verify that the correct search_path restored on abort
21+
SET search_path to public;
22+
BEGIN;
23+
SET search_path to public, test_ns_schema_1;
24+
CREATESCHEMAtest_ns_schema_2
25+
CREATEVIEWabc_viewASSELECT cFROM abc;
26+
COMMIT;
27+
SHOW search_path;
28+
29+
-- verify that the correct search_path preserved
30+
-- after creating the schema and on commit
31+
BEGIN;
32+
SET search_path to public, test_ns_schema_1;
33+
CREATESCHEMAtest_ns_schema_2
34+
CREATEVIEWabc_viewASSELECT aFROM abc;
35+
SHOW search_path;
36+
COMMIT;
37+
SHOW search_path;
38+
DROPSCHEMA test_ns_schema_2 CASCADE;
39+
1640
-- verify that the objects were created
1741
SELECTCOUNT(*)FROM pg_classWHERE relnamespace=
1842
(SELECToidFROM pg_namespaceWHERE nspname='test_ns_schema_1');

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp