From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346AbdBMNVw (ORCPT ); Mon, 13 Feb 2017 08:21:52 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42594 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752826AbdBMNEp (ORCPT ); Mon, 13 Feb 2017 08:04:45 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, artem@flashgrid.io, Mike Snitzer Subject: [PATCH 4.9 05/60] dm rq: cope with DM device destruction while in dm_old_request_fn() Date: Mon, 13 Feb 2017 05:03:37 -0800 Message-Id: <20170213130333.814598317@linuxfoundation.org> X-Mailer: git-send-email 2.11.1 In-Reply-To: <20170213130333.057515084@linuxfoundation.org> References: <20170213130333.057515084@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Snitzer commit 4087a1fffe38106e10646606a27f10d40451862d upstream. Fixes a crash in dm_table_find_target() due to a NULL struct dm_table being passed from dm_old_request_fn() that races with DM device destruction. Reported-by: artem@flashgrid.io Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-rq.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -804,6 +804,10 @@ static void dm_old_request_fn(struct req int srcu_idx; struct dm_table *map = dm_get_live_table(md, &srcu_idx); + if (unlikely(!map)) { + dm_put_live_table(md, srcu_idx); + return; + } ti = dm_table_find_target(map, pos); dm_put_live_table(md, srcu_idx); }