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

Commit3d0f68d

Browse files
committed
Fix corner-case failures in has_foo_privilege() family of functions.
The variants of these functions that take numeric inputs (OIDs orcolumn numbers) are supposed to return NULL rather than failingon bad input; this rule reduces problems with snapshot skew whenqueries apply the functions to all rows of a catalog.has_column_privilege() had careless handling of the case where thetable OID didn't exist. You might get something like this:select has_column_privilege(9999,'nosuchcol','select');ERROR: column "nosuchcol" of relation "(null)" does not existor you might get a crash, depending on the platform's printf's responseto a null string pointer.In addition, while applying the column-number variant to a droppedcolumn returned NULL as desired, applying the column-name variantdid not:select has_column_privilege('mytable','........pg.dropped.2........','select');ERROR: column "........pg.dropped.2........" of relation "mytable" does not existIt seems better to make this case return NULL as well.Also, the OID-accepting variants of has_foreign_data_wrapper_privilege,has_server_privilege, and has_tablespace_privilege didn't follow theprinciple of returning NULL for nonexistent OIDs. Superusers got TRUE,everybody else got an error.Per investigation of Jaime Casanova's report of a new crash in HEAD.These behaviors have been like this for a long time, so back-patch toall supported branches.Patch by me; thanks to Stephen Frost for discussion and reviewDiscussion:https://postgr.es/m/CAJGNTeP=-6Gyqq5TN9OvYEydi7Fv1oGyYj650LGTnW44oAzYCg@mail.gmail.com
1 parent80810ca commit3d0f68d

File tree

3 files changed

+159
-10
lines changed

3 files changed

+159
-10
lines changed

‎src/backend/utils/adt/acl.c

Lines changed: 85 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -2447,8 +2447,12 @@ has_any_column_privilege_id_id(PG_FUNCTION_ARGS)
24472447
*
24482448
*The result is a boolean value: true if user has the indicated
24492449
*privilege, false if not. The variants that take a relation OID
2450-
*and an integer attnum return NULL (rather than throwing an error)
2451-
*if the column doesn't exist or is dropped.
2450+
*return NULL (rather than throwing an error) if that relation OID
2451+
*doesn't exist. Likewise, the variants that take an integer attnum
2452+
*return NULL (rather than throwing an error) if there is no such
2453+
*pg_attribute entry. All variants return NULL if an attisdropped
2454+
*column is selected. These rules are meant to avoid unnecessary
2455+
*failures in queries that scan pg_attribute.
24522456
*/
24532457

24542458
/*
@@ -2465,6 +2469,12 @@ column_privilege_check(Oid tableoid, AttrNumber attnum,
24652469
HeapTupleattTuple;
24662470
Form_pg_attributeattributeForm;
24672471

2472+
/*
2473+
* If convert_column_name failed, we can just return -1 immediately.
2474+
*/
2475+
if (attnum==InvalidAttrNumber)
2476+
return-1;
2477+
24682478
/*
24692479
* First check if we have the privilege at the table level. We check
24702480
* existence of the pg_class row before risking calling pg_class_aclcheck.
@@ -2826,21 +2836,59 @@ has_column_privilege_id_attnum(PG_FUNCTION_ARGS)
28262836

28272837
/*
28282838
* Given a table OID and a column name expressed as a string, look it up
2829-
* and return the column number
2839+
* and return the column number. Returns InvalidAttrNumber in cases
2840+
* where caller should return NULL instead of failing.
28302841
*/
28312842
staticAttrNumber
28322843
convert_column_name(Oidtableoid,text*column)
28332844
{
2834-
AttrNumberattnum;
28352845
char*colname;
2846+
HeapTupleattTuple;
2847+
AttrNumberattnum;
28362848

28372849
colname=text_to_cstring(column);
2838-
attnum=get_attnum(tableoid,colname);
2839-
if (attnum==InvalidAttrNumber)
2840-
ereport(ERROR,
2841-
(errcode(ERRCODE_UNDEFINED_COLUMN),
2842-
errmsg("column \"%s\" of relation \"%s\" does not exist",
2843-
colname,get_rel_name(tableoid))));
2850+
2851+
/*
2852+
* We don't use get_attnum() here because it will report that dropped
2853+
* columns don't exist. We need to treat dropped columns differently from
2854+
* nonexistent columns.
2855+
*/
2856+
attTuple=SearchSysCache2(ATTNAME,
2857+
ObjectIdGetDatum(tableoid),
2858+
CStringGetDatum(colname));
2859+
if (HeapTupleIsValid(attTuple))
2860+
{
2861+
Form_pg_attributeattributeForm;
2862+
2863+
attributeForm= (Form_pg_attribute)GETSTRUCT(attTuple);
2864+
/* We want to return NULL for dropped columns */
2865+
if (attributeForm->attisdropped)
2866+
attnum=InvalidAttrNumber;
2867+
else
2868+
attnum=attributeForm->attnum;
2869+
ReleaseSysCache(attTuple);
2870+
}
2871+
else
2872+
{
2873+
char*tablename=get_rel_name(tableoid);
2874+
2875+
/*
2876+
* If the table OID is bogus, or it's just been dropped, we'll get
2877+
* NULL back. In such cases we want has_column_privilege to return
2878+
* NULL too, so just return InvalidAttrNumber.
2879+
*/
2880+
if (tablename!=NULL)
2881+
{
2882+
/* tableoid exists, colname does not, so throw error */
2883+
ereport(ERROR,
2884+
(errcode(ERRCODE_UNDEFINED_COLUMN),
2885+
errmsg("column \"%s\" of relation \"%s\" does not exist",
2886+
colname,tablename)));
2887+
}
2888+
/* tableoid doesn't exist, so act like attisdropped case */
2889+
attnum=InvalidAttrNumber;
2890+
}
2891+
28442892
pfree(colname);
28452893
returnattnum;
28462894
}
@@ -3144,6 +3192,9 @@ has_foreign_data_wrapper_privilege_name_id(PG_FUNCTION_ARGS)
31443192
roleid=get_role_oid_or_public(NameStr(*username));
31453193
mode=convert_foreign_data_wrapper_priv_string(priv_type_text);
31463194

3195+
if (!SearchSysCacheExists1(FOREIGNDATAWRAPPEROID,ObjectIdGetDatum(fdwid)))
3196+
PG_RETURN_NULL();
3197+
31473198
aclresult=pg_foreign_data_wrapper_aclcheck(fdwid,roleid,mode);
31483199

31493200
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -3167,6 +3218,9 @@ has_foreign_data_wrapper_privilege_id(PG_FUNCTION_ARGS)
31673218
roleid=GetUserId();
31683219
mode=convert_foreign_data_wrapper_priv_string(priv_type_text);
31693220

3221+
if (!SearchSysCacheExists1(FOREIGNDATAWRAPPEROID,ObjectIdGetDatum(fdwid)))
3222+
PG_RETURN_NULL();
3223+
31703224
aclresult=pg_foreign_data_wrapper_aclcheck(fdwid,roleid,mode);
31713225

31723226
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -3211,6 +3265,9 @@ has_foreign_data_wrapper_privilege_id_id(PG_FUNCTION_ARGS)
32113265

32123266
mode=convert_foreign_data_wrapper_priv_string(priv_type_text);
32133267

3268+
if (!SearchSysCacheExists1(FOREIGNDATAWRAPPEROID,ObjectIdGetDatum(fdwid)))
3269+
PG_RETURN_NULL();
3270+
32143271
aclresult=pg_foreign_data_wrapper_aclcheck(fdwid,roleid,mode);
32153272

32163273
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -3910,6 +3967,9 @@ has_server_privilege_name_id(PG_FUNCTION_ARGS)
39103967
roleid=get_role_oid_or_public(NameStr(*username));
39113968
mode=convert_server_priv_string(priv_type_text);
39123969

3970+
if (!SearchSysCacheExists1(FOREIGNSERVEROID,ObjectIdGetDatum(serverid)))
3971+
PG_RETURN_NULL();
3972+
39133973
aclresult=pg_foreign_server_aclcheck(serverid,roleid,mode);
39143974

39153975
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -3933,6 +3993,9 @@ has_server_privilege_id(PG_FUNCTION_ARGS)
39333993
roleid=GetUserId();
39343994
mode=convert_server_priv_string(priv_type_text);
39353995

3996+
if (!SearchSysCacheExists1(FOREIGNSERVEROID,ObjectIdGetDatum(serverid)))
3997+
PG_RETURN_NULL();
3998+
39363999
aclresult=pg_foreign_server_aclcheck(serverid,roleid,mode);
39374000

39384001
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -3977,6 +4040,9 @@ has_server_privilege_id_id(PG_FUNCTION_ARGS)
39774040

39784041
mode=convert_server_priv_string(priv_type_text);
39794042

4043+
if (!SearchSysCacheExists1(FOREIGNSERVEROID,ObjectIdGetDatum(serverid)))
4044+
PG_RETURN_NULL();
4045+
39804046
aclresult=pg_foreign_server_aclcheck(serverid,roleid,mode);
39814047

39824048
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -4092,6 +4158,9 @@ has_tablespace_privilege_name_id(PG_FUNCTION_ARGS)
40924158
roleid=get_role_oid_or_public(NameStr(*username));
40934159
mode=convert_tablespace_priv_string(priv_type_text);
40944160

4161+
if (!SearchSysCacheExists1(TABLESPACEOID,ObjectIdGetDatum(tablespaceoid)))
4162+
PG_RETURN_NULL();
4163+
40954164
aclresult=pg_tablespace_aclcheck(tablespaceoid,roleid,mode);
40964165

40974166
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -4115,6 +4184,9 @@ has_tablespace_privilege_id(PG_FUNCTION_ARGS)
41154184
roleid=GetUserId();
41164185
mode=convert_tablespace_priv_string(priv_type_text);
41174186

4187+
if (!SearchSysCacheExists1(TABLESPACEOID,ObjectIdGetDatum(tablespaceoid)))
4188+
PG_RETURN_NULL();
4189+
41184190
aclresult=pg_tablespace_aclcheck(tablespaceoid,roleid,mode);
41194191

41204192
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);
@@ -4159,6 +4231,9 @@ has_tablespace_privilege_id_id(PG_FUNCTION_ARGS)
41594231

41604232
mode=convert_tablespace_priv_string(priv_type_text);
41614233

4234+
if (!SearchSysCacheExists1(TABLESPACEOID,ObjectIdGetDatum(tablespaceoid)))
4235+
PG_RETURN_NULL();
4236+
41624237
aclresult=pg_tablespace_aclcheck(tablespaceoid,roleid,mode);
41634238

41644239
PG_RETURN_BOOL(aclresult==ACLCHECK_OK);

‎src/test/regress/expected/privileges.out

Lines changed: 57 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1132,6 +1132,63 @@ from (select oid from pg_class where relname = 'atest1') as t1;
11321132
f
11331133
(1 row)
11341134

1135+
-- has_column_privilege function
1136+
-- bad-input checks (as non-super-user)
1137+
select has_column_privilege('pg_authid',NULL,'select');
1138+
has_column_privilege
1139+
----------------------
1140+
1141+
(1 row)
1142+
1143+
select has_column_privilege('pg_authid','nosuchcol','select');
1144+
ERROR: column "nosuchcol" of relation "pg_authid" does not exist
1145+
select has_column_privilege(9999,'nosuchcol','select');
1146+
has_column_privilege
1147+
----------------------
1148+
1149+
(1 row)
1150+
1151+
select has_column_privilege(9999,99::int2,'select');
1152+
has_column_privilege
1153+
----------------------
1154+
1155+
(1 row)
1156+
1157+
select has_column_privilege('pg_authid',99::int2,'select');
1158+
has_column_privilege
1159+
----------------------
1160+
1161+
(1 row)
1162+
1163+
select has_column_privilege(9999,99::int2,'select');
1164+
has_column_privilege
1165+
----------------------
1166+
1167+
(1 row)
1168+
1169+
create temp table mytable(f1 int, f2 int, f3 int);
1170+
alter table mytable drop column f2;
1171+
select has_column_privilege('mytable','f2','select');
1172+
ERROR: column "f2" of relation "mytable" does not exist
1173+
select has_column_privilege('mytable','........pg.dropped.2........','select');
1174+
has_column_privilege
1175+
----------------------
1176+
1177+
(1 row)
1178+
1179+
select has_column_privilege('mytable',2::int2,'select');
1180+
has_column_privilege
1181+
----------------------
1182+
t
1183+
(1 row)
1184+
1185+
revoke select on table mytable from regress_priv_user3;
1186+
select has_column_privilege('mytable',2::int2,'select');
1187+
has_column_privilege
1188+
----------------------
1189+
1190+
(1 row)
1191+
11351192
-- Grant options
11361193
SET SESSION AUTHORIZATION regress_priv_user1;
11371194
CREATE TABLE atest4 (a int);

‎src/test/regress/sql/privileges.sql

Lines changed: 17 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -715,6 +715,23 @@ from (select oid from pg_class where relname = 'atest1') as t1;
715715
select has_table_privilege(t1.oid,'trigger')
716716
from (selectoidfrom pg_classwhere relname='atest1')as t1;
717717

718+
-- has_column_privilege function
719+
720+
-- bad-input checks (as non-super-user)
721+
select has_column_privilege('pg_authid',NULL,'select');
722+
select has_column_privilege('pg_authid','nosuchcol','select');
723+
select has_column_privilege(9999,'nosuchcol','select');
724+
select has_column_privilege(9999,99::int2,'select');
725+
select has_column_privilege('pg_authid',99::int2,'select');
726+
select has_column_privilege(9999,99::int2,'select');
727+
728+
create temp table mytable(f1int, f2int, f3int);
729+
altertable mytable drop column f2;
730+
select has_column_privilege('mytable','f2','select');
731+
select has_column_privilege('mytable','........pg.dropped.2........','select');
732+
select has_column_privilege('mytable',2::int2,'select');
733+
revokeselecton table mytablefrom regress_priv_user3;
734+
select has_column_privilege('mytable',2::int2,'select');
718735

719736
-- Grant options
720737

0 commit comments

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