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Fix ExecCheckPermissions call in RI_Initial_Check

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RI_Initial_Check was setting up a list of RTEPermissionInfo for
ExecCheckPermissions() wrong, and the problem is subtle enough that it
doesn't have any immediate effect in core code.  However, if an
extension is using the ExecutorCheckPerms_hook, then it would get the
wrong parameters and perhaps arrive at a wrong conclusion, or outright
malfunction.  Fix by constructing that list and the RTE list more
honestly.

We also add an assertion check to verify that these lists match.  This
new assertion would have caught this bug.

Co-authored-by: Олег Целебровский (Oleg Tselebrovskii) <o.tselebrovskiy@postgrespro.ru>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/3722b7a2cbe27a1796ee40824bd86dd1@postgrespro.ru
This commit is contained in:
Alvaro Herrera 2023-05-04 19:55:56 +02:00
parent 4c40995f61
commit f75cec4fff
No known key found for this signature in database
GPG Key ID: 1C20ACB9D5C564AE
2 changed files with 46 additions and 18 deletions
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22
src/backend/executor/execMain.c
View File

@ -584,6 +584,28 @@ ExecCheckPermissions(List *rangeTable, List *rteperminfos,
ListCell *l;
bool result = true;
#ifdef USE_ASSERT_CHECKING
Bitmapset *indexset = NULL;
/* Check that rteperminfos is consistent with rangeTable */
foreach(l, rangeTable)
{
RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
if (rte->perminfoindex != 0)
{
/* Sanity checks */
(void) getRTEPermissionInfo(rteperminfos, rte);
/* Many-to-one mapping not allowed */
Assert(!bms_is_member(rte->perminfoindex, indexset));
indexset = bms_add_member(indexset, rte->perminfoindex);
}
}
/* All rteperminfos are referenced */
Assert(bms_num_members(indexset) == list_length(rteperminfos));
#endif
foreach(l, rteperminfos)
{
RTEPermissionInfo *perminfo = lfirst_node(RTEPermissionInfo, l);

42
src/backend/utils/adt/ri_triggers.c
View File

@ -1373,10 +1373,11 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
char fkrelname[MAX_QUOTED_REL_NAME_LEN];
char pkattname[MAX_QUOTED_NAME_LEN + 3];
char fkattname[MAX_QUOTED_NAME_LEN + 3];
RangeTblEntry *pkrte;
RangeTblEntry *fkrte;
RangeTblEntry *rte;
RTEPermissionInfo *pk_perminfo;
RTEPermissionInfo *fk_perminfo;
List *rtes = NIL;
List *perminfos = NIL;
const char *sep;
const char *fk_only;
const char *pk_only;
@ -1394,25 +1395,29 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
*
* XXX are there any other show-stopper conditions to check?
*/
pkrte = makeNode(RangeTblEntry);
pkrte->rtekind = RTE_RELATION;
pkrte->relid = RelationGetRelid(pk_rel);
pkrte->relkind = pk_rel->rd_rel->relkind;
pkrte->rellockmode = AccessShareLock;
pk_perminfo = makeNode(RTEPermissionInfo);
pk_perminfo->relid = RelationGetRelid(pk_rel);
pk_perminfo->requiredPerms = ACL_SELECT;
fkrte = makeNode(RangeTblEntry);
fkrte->rtekind = RTE_RELATION;
fkrte->relid = RelationGetRelid(fk_rel);
fkrte->relkind = fk_rel->rd_rel->relkind;
fkrte->rellockmode = AccessShareLock;
perminfos = lappend(perminfos, pk_perminfo);
rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = RelationGetRelid(pk_rel);
rte->relkind = pk_rel->rd_rel->relkind;
rte->rellockmode = AccessShareLock;
rte->perminfoindex = list_length(perminfos);
rtes = lappend(rtes, rte);
fk_perminfo = makeNode(RTEPermissionInfo);
fk_perminfo->relid = RelationGetRelid(fk_rel);
fk_perminfo->requiredPerms = ACL_SELECT;
perminfos = lappend(perminfos, fk_perminfo);
rte = makeNode(RangeTblEntry);
rte->rtekind = RTE_RELATION;
rte->relid = RelationGetRelid(fk_rel);
rte->relkind = fk_rel->rd_rel->relkind;
rte->rellockmode = AccessShareLock;
rte->perminfoindex = list_length(perminfos);
rtes = lappend(rtes, rte);
for (int i = 0; i < riinfo->nkeys; i++)
{
@ -1425,8 +1430,7 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
fk_perminfo->selectedCols = bms_add_member(fk_perminfo->selectedCols, attno);
}
if (!ExecCheckPermissions(list_make2(fkrte, pkrte),
list_make2(fk_perminfo, pk_perminfo), false))
if (!ExecCheckPermissions(rtes, perminfos, false))
return false;
/*
@ -1436,9 +1440,11 @@ RI_Initial_Check(Trigger *trigger, Relation fk_rel, Relation pk_rel)
*/
if (!has_bypassrls_privilege(GetUserId()) &&
((pk_rel->rd_rel->relrowsecurity &&
!object_ownercheck(RelationRelationId, pkrte->relid, GetUserId())) ||
!object_ownercheck(RelationRelationId, RelationGetRelid(pk_rel),
GetUserId())) ||
(fk_rel->rd_rel->relrowsecurity &&
!object_ownercheck(RelationRelationId, fkrte->relid, GetUserId()))))
!object_ownercheck(RelationRelationId, RelationGetRelid(fk_rel),
GetUserId()))))
return false;
/*----------