Fix ALTER EXTENSION SET SCHEMA with objects outside an extension's schema

michaelpq · michaelpq · commit 914e72e6e8d3 · 2023-07-10T09:40:24.000+09:00
As coded, the code would use as a base comparison the namespace OID from the first object scanned in pg_depend when switching its namespace dependency entry to the new one, and use it as a base of comparison for any follow-up checks. It would also be used as the old namespace OID to switch *from* for the extension's pg_depend entry. Hence, if the first object scanned has a namespace different than the one stored in the extension, we would finish by: - Not checking that the extension objects map with the extension's schema. - Not switching the extension -> namespace dependency entry to the new namespace provided by the user, making ALTER EXTENSION ineffective. This issue exists since this command has been introduced in d9572c4 for relocatable extension, so backpatch all the way down to 11. The test case has been provided by Heikki, that I have tweaked a bit to show the effects on pg_depend for the extension. Reported-by: Heikki Linnakangas Author: Michael Paquier, Heikki Linnakangas Discussion: https://postgr.es/m/20eea594-a05b-4c31-491b-007b6fceef28@iki.fi Backpatch-through: 11
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
@@ -2702,7 +2702,7 @@ AlterExtensionNamespace(const char *extensionName, const char *newschema, Oid *o
 {
 	Oid			extensionOid;
 	Oid			nspOid;
-	Oid			oldNspOid = InvalidOid;
+	Oid			oldNspOid;
 	AclResult	aclresult;
 	Relation	extRel;
 	ScanKeyData key[2];
@@ -2785,6 +2785,9 @@ AlterExtensionNamespace(const char *extensionName, const char *newschema, Oid *o
 
 	objsMoved = new_object_addresses();
 
+	/* store the OID of the namespace to-be-changed */
+	oldNspOid = extForm->extnamespace;
+
 	/*
 	 * Scan pg_depend to find objects that depend directly on the extension,
 	 * and alter each one's schema.
@@ -2830,12 +2833,6 @@ AlterExtensionNamespace(const char *extensionName, const char *newschema, Oid *o
 												 nspOid,
 												 objsMoved);
 
-		/*
-		 * Remember previous namespace of first object that has one
-		 */
-		if (oldNspOid == InvalidOid && dep_oldNspOid != InvalidOid)
-			oldNspOid = dep_oldNspOid;
-
 		/*
 		 * If not all the objects had the same old namespace (ignoring any
 		 * that are not in namespaces), complain.
