From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752151AbdKVCfo (ORCPT ); Tue, 21 Nov 2017 21:35:44 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56769 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751858AbdKVCUY (ORCPT ); Tue, 21 Nov 2017 21:20:24 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Coly Li" , "Tony Asleson" , "Jens Axboe" Date: Wed, 22 Nov 2017 01:58:13 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 101/133] bcache: Correct return value for sysfs attach errors In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Tony Asleson commit 77fa100f27475d08a569b9d51c17722130f089e7 upstream. If you encounter any errors in bch_cached_dev_attach it will return a negative error code. The variable 'v' which stores the result is unsigned, thus user space sees a very large value returned for bytes written which can cause incorrect user space behavior. Utilize 1 signed variable to use throughout the function to preserve error return capability. Signed-off-by: Tony Asleson Acked-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings --- drivers/md/bcache/sysfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -191,7 +191,7 @@ STORE(__cached_dev) { struct cached_dev *dc = container_of(kobj, struct cached_dev, disk.kobj); - unsigned v = size; + ssize_t v = size; struct cache_set *c; struct kobj_uevent_env *env; @@ -226,7 +226,7 @@ STORE(__cached_dev) bch_cached_dev_run(dc); if (attr == &sysfs_cache_mode) { - ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1); + v = bch_read_string_list(buf, bch_cache_modes + 1); if (v < 0) return v;