From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754637AbdJPQM1 (ORCPT ); Mon, 16 Oct 2017 12:12:27 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33220 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754622AbdJPQMX (ORCPT ); Mon, 16 Oct 2017 12:12:23 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Gruenbacher , Jan Kara , Al Viro Subject: [PATCH 3.18 13/19] direct-io: Prevent NULL pointer access in submit_page_section Date: Mon, 16 Oct 2017 18:12:04 +0200 Message-Id: <20171016160922.703062948@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171016160922.020176454@linuxfoundation.org> References: <20171016160922.020176454@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 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andreas Gruenbacher commit 899f0429c7d3eed886406cd72182bee3b96aa1f9 upstream. In the code added to function submit_page_section by commit b1058b981, sdio->bio can currently be NULL when calling dio_bio_submit. This then leads to a NULL pointer access in dio_bio_submit, so check for a NULL bio in submit_page_section before trying to submit it instead. Fixes xfstest generic/250 on gfs2. Signed-off-by: Andreas Gruenbacher Reviewed-by: Jan Kara Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- fs/direct-io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -812,7 +812,8 @@ out: */ if (sdio->boundary) { ret = dio_send_cur_page(dio, sdio, map_bh); - dio_bio_submit(dio, sdio); + if (sdio->bio) + dio_bio_submit(dio, sdio); page_cache_release(sdio->cur_page); sdio->cur_page = NULL; }