Make inherited TRUNCATE perform access permission checks on parent table only.

Previously, TRUNCATE command through a parent table checked the
permissions on not only the parent table but also the children tables
inherited from it. This was a bug and inherited queries should perform
access permission checks on the parent table only. This commit fixes
that bug.

Back-patch to all supported branches.

Author: Amit Langote
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CAHGQGwFHdSvifhJE+-GSNqUHSfbiKxaeQQ7HGcYz6SC2n_oDcg@mail.gmail.com
This commit is contained in:
Fujii Masao 2020-01-31 00:42:06 +09:00
parent b0afdcad21
commit e6f1e560e4
3 changed files with 60 additions and 7 deletions

View File

@ -304,6 +304,7 @@ struct DropRelationCallbackState
((child_is_partition) ? DEPENDENCY_AUTO : DEPENDENCY_NORMAL)
static void truncate_check_rel(Oid relid, Form_pg_class reltuple);
static void truncate_check_perms(Oid relid, Form_pg_class reltuple);
static void truncate_check_activity(Relation rel);
static void RangeVarCallbackForTruncate(const RangeVar *relation,
Oid relId, Oid oldRelId, void *arg);
@ -1615,6 +1616,12 @@ ExecuteTruncate(TruncateStmt *stmt)
continue;
}
/*
* Inherited TRUNCATE commands perform access
* permission checks on the parent table only.
* So we skip checking the children's permissions
* and don't call truncate_check_perms() here.
*/
truncate_check_rel(RelationGetRelid(rel), rel->rd_rel);
truncate_check_activity(rel);
@ -1701,6 +1708,7 @@ ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged,
(errmsg("truncate cascades to table \"%s\"",
RelationGetRelationName(rel))));
truncate_check_rel(relid, rel->rd_rel);
truncate_check_perms(relid, rel->rd_rel);
truncate_check_activity(rel);
rels = lappend(rels, rel);
relids = lappend_oid(relids, relid);
@ -1951,7 +1959,6 @@ ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged,
static void
truncate_check_rel(Oid relid, Form_pg_class reltuple)
{
AclResult aclresult;
char *relname = NameStr(reltuple->relname);
/*
@ -1965,12 +1972,6 @@ truncate_check_rel(Oid relid, Form_pg_class reltuple)
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table", relname)));
/* Permissions checks */
aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_TRUNCATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_relkind_objtype(reltuple->relkind),
relname);
if (!allowSystemTableMods && IsSystemClass(relid, reltuple))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
@ -1980,6 +1981,22 @@ truncate_check_rel(Oid relid, Form_pg_class reltuple)
InvokeObjectTruncateHook(relid);
}
/*
* Check that current user has the permission to truncate given relation.
*/
static void
truncate_check_perms(Oid relid, Form_pg_class reltuple)
{
char *relname = NameStr(reltuple->relname);
AclResult aclresult;
/* Permissions checks */
aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_TRUNCATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_relkind_objtype(reltuple->relkind),
relname);
}
/*
* Set of extra sanity checks to check if a given relation is safe to
* truncate. This is split with truncate_check_rel() as
@ -15292,6 +15309,7 @@ RangeVarCallbackForTruncate(const RangeVar *relation,
elog(ERROR, "cache lookup failed for relation %u", relId);
truncate_check_rel(relId, (Form_pg_class) GETSTRUCT(tuple));
truncate_check_perms(relId, (Form_pg_class) GETSTRUCT(tuple));
ReleaseSysCache(tuple);
}

View File

@ -695,6 +695,27 @@ SELECT tableoid FROM atestp2; -- ok
----------
(0 rows)
-- child's permissions do not apply when operating on parent
SET SESSION AUTHORIZATION regress_priv_user1;
REVOKE ALL ON atestc FROM regress_priv_user2;
GRANT ALL ON atestp1 TO regress_priv_user2;
SET SESSION AUTHORIZATION regress_priv_user2;
SELECT f2 FROM atestp1; -- ok
f2
----
(0 rows)
SELECT f2 FROM atestc; -- fail
ERROR: permission denied for table atestc
DELETE FROM atestp1; -- ok
DELETE FROM atestc; -- fail
ERROR: permission denied for table atestc
UPDATE atestp1 SET f1 = 1; -- ok
UPDATE atestc SET f1 = 1; -- fail
ERROR: permission denied for table atestc
TRUNCATE atestp1; -- ok
TRUNCATE atestc; -- fail
ERROR: permission denied for table atestc
-- privileges on functions, languages
-- switch to superuser
\c -

View File

@ -446,6 +446,20 @@ SELECT fy FROM atestp2; -- ok
SELECT atestp2 FROM atestp2; -- ok
SELECT tableoid FROM atestp2; -- ok
-- child's permissions do not apply when operating on parent
SET SESSION AUTHORIZATION regress_priv_user1;
REVOKE ALL ON atestc FROM regress_priv_user2;
GRANT ALL ON atestp1 TO regress_priv_user2;
SET SESSION AUTHORIZATION regress_priv_user2;
SELECT f2 FROM atestp1; -- ok
SELECT f2 FROM atestc; -- fail
DELETE FROM atestp1; -- ok
DELETE FROM atestc; -- fail
UPDATE atestp1 SET f1 = 1; -- ok
UPDATE atestc SET f1 = 1; -- fail
TRUNCATE atestp1; -- ok
TRUNCATE atestc; -- fail
-- privileges on functions, languages
-- switch to superuser