Fix "unexpected relkind" error when denying permissions on toast tables.

get_relkind_objtype, and hence get_object_type, failed when applied to a
toast table.  This is not a good thing, because it prevents reporting of
perfectly legitimate permissions errors.  (At present, these functions
are in fact *only* used to determine the ObjectType argument for
acl_error() calls.)  It seems best to have them fall back to returning
OBJECT_TABLE in every case where they can't determine an object type
for a pg_class entry, so do that.

In passing, make some edits to alter.c to make it more obvious that
those calls of get_object_type() are used only for error reporting.
This might save a few cycles in the non-error code path, too.

Back-patch to v11 where this issue originated.

John Hsu, Michael Paquier, Tom Lane

Discussion: https://postgr.es/m/C652D3DF-2B0C-4128-9420-FB5379F6B1E4@amazon.com

1 files changed, 5 insertions, 7 deletions

diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index eff325cc7d0..4d443c13292 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -171,7 +171,6 @@ AlterObjectRename_internal(Relation rel, Oid objectId, const char *new_name)
 	AttrNumber	Anum_name = get_object_attnum_name(classId);
 	AttrNumber	Anum_namespace = get_object_attnum_namespace(classId);
 	AttrNumber	Anum_owner = get_object_attnum_owner(classId);
-	ObjectType	objtype = get_object_type(classId, objectId);
 	HeapTuple	oldtup;
 	HeapTuple	newtup;
 	Datum		datum;
@@ -223,7 +222,8 @@ AlterObjectRename_internal(Relation rel, Oid objectId, const char *new_name)
 		ownerId = DatumGetObjectId(datum);
 
 		if (!has_privs_of_role(GetUserId(), DatumGetObjectId(ownerId)))
-			aclcheck_error(ACLCHECK_NOT_OWNER, objtype, old_name);
+			aclcheck_error(ACLCHECK_NOT_OWNER, get_object_type(classId, objectId),
+						   old_name);
 
 		/* User must have CREATE privilege on the namespace */
 		if (OidIsValid(namespaceId))
@@ -663,7 +663,6 @@ AlterObjectNamespace_internal(Relation rel, Oid objid, Oid nspOid)
 	AttrNumber	Anum_name = get_object_attnum_name(classId);
 	AttrNumber	Anum_namespace = get_object_attnum_namespace(classId);
 	AttrNumber	Anum_owner = get_object_attnum_owner(classId);
-	ObjectType	objtype = get_object_type(classId, objid);
 	Oid			oldNspOid;
 	Datum		name,
 				namespace;
@@ -719,7 +718,7 @@ AlterObjectNamespace_internal(Relation rel, Oid objid, Oid nspOid)
 		ownerId = DatumGetObjectId(owner);
 
 		if (!has_privs_of_role(GetUserId(), ownerId))
-			aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
+			aclcheck_error(ACLCHECK_NOT_OWNER, get_object_type(classId, objid),
 						   NameStr(*(DatumGetName(name))));
 
 		/* User must have CREATE privilege on new namespace */
@@ -942,8 +941,6 @@ AlterObjectOwner_internal(Relation rel, Oid objectId, Oid new_ownerId)
 		/* Superusers can bypass permission checks */
 		if (!superuser())
 		{
-			ObjectType	objtype = get_object_type(classId, objectId);
-
 			/* must be owner */
 			if (!has_privs_of_role(GetUserId(), old_ownerId))
 			{
@@ -963,7 +960,8 @@ AlterObjectOwner_internal(Relation rel, Oid objectId, Oid new_ownerId)
 							 HeapTupleGetOid(oldtup));
 					objname = namebuf;
 				}
-				aclcheck_error(ACLCHECK_NOT_OWNER, objtype, objname);
+				aclcheck_error(ACLCHECK_NOT_OWNER, get_object_type(classId, objectId),
+							   objname);
 			}
 			/* Must be able to become new owner */
 			check_is_member_of_role(GetUserId(), new_ownerId);