Path: csiph.com!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod From: Greg Kroah-Hartman Newsgroups: linux.kernel Subject: [PATCH 4.4 061/118] dm log writes: fix check of kthread_run() return value Date: Thu, 22 Sep 2016 19:40:02 +0200 Message-ID: References: X-Original-To: linux-kernel@vger.kernel.org X-Mailer: git-send-email 2.10.0 User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 34 Organization: linux.* mail to news gateway X-Original-Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vladimir Zapolskiy , Mike Snitzer X-Original-Date: Thu, 22 Sep 2016 19:29:21 +0200 X-Original-Message-ID: <20160922172941.818082622@linuxfoundation.org> X-Original-References: <20160922172938.643879685@linuxfoundation.org> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1489128 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vladimir Zapolskiy commit 91e630d9ae6de6f740ef7c8176736eb55366833e upstream. The kthread_run() function returns either a valid task_struct or ERR_PTR() value, check for NULL is invalid. This change fixes potential for oops, e.g. in OOM situation. Signed-off-by: Vladimir Zapolskiy Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-log-writes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm-log-writes.c +++ b/drivers/md/dm-log-writes.c @@ -456,9 +456,9 @@ static int log_writes_ctr(struct dm_targ goto bad; } - ret = -EINVAL; lc->log_kthread = kthread_run(log_writes_kthread, lc, "log-write"); - if (!lc->log_kthread) { + if (IS_ERR(lc->log_kthread)) { + ret = PTR_ERR(lc->log_kthread); ti->error = "Couldn't alloc kthread"; dm_put_device(ti, lc->dev); dm_put_device(ti, lc->logdev);