From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0565C282C0 for ; Sun, 27 Jan 2019 04:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AABF62148D for ; Sun, 27 Jan 2019 04:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726453AbfA0E6Q (ORCPT ); Sat, 26 Jan 2019 23:58:16 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:48840 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726404AbfA0E6Q (ORCPT ); Sat, 26 Jan 2019 23:58:16 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.91 #2 (Red Hat Linux)) id 1gncW8-00041p-9X; Sun, 27 Jan 2019 04:58:05 +0000 Date: Sun, 27 Jan 2019 04:58:00 +0000 From: Al Viro To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH] btrfs: oops in device_list_add() Message-ID: <20190127045755.GH2217@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org alloc_fs_devices() can return ERR_PTR(-ENOMEM), so dereferencing its result before the check for IS_ERR() is a bad idea... Fixes: d1a63002829a4 Signed-off-by: Al Viro --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 85149f27644d..72adc5643bde 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -955,11 +955,11 @@ static noinline struct btrfs_device *device_list_add(const char *path, else fs_devices = alloc_fs_devices(disk_super->fsid, NULL); - fs_devices->fsid_change = fsid_change_in_progress; - if (IS_ERR(fs_devices)) return ERR_CAST(fs_devices); + fs_devices->fsid_change = fsid_change_in_progress; + mutex_lock(&fs_devices->device_list_mutex); list_add(&fs_devices->fs_list, &fs_uuids);