Merge pull request #41131 from nextcloud/backport/41123/stable20

[stable20] fix(external): Get storage before update it

apps/files_external/lib/Service/UserStoragesService.php

@@ -124,6 +124,9 @@ class UserStoragesService extends StoragesService {
 	 * @throws NotFoundException if the given storage does not exist in the config
 	 */
 	public function updateStorage(StorageConfig $updatedStorage) {
+		// verify ownership through $this->isApplicable() and otherwise throws an exception
+		$this->getStorage($updatedStorage->getId());
+
 		$updatedStorage->setApplicableUsers([$this->getUser()->getUID()]);
 		return parent::updateStorage($updatedStorage);
 	}