From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934026AbdKAV1m (ORCPT ); Wed, 1 Nov 2017 17:27:42 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:35262 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934000AbdKAV1i (ORCPT ); Wed, 1 Nov 2017 17:27:38 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Andreas Gruenbacher , Al Viro , Willy Tarreau Subject: [PATCH 3.10 054/139] direct-io: Prevent NULL pointer access in submit_page_section Date: Wed, 1 Nov 2017 22:25:55 +0100 Message-Id: <1509571600-4858-5-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1509571600-4858-1-git-send-email-w@1wt.eu> References: <1509571159-4405-1-git-send-email-w@1wt.eu> <1509571600-4858-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Cc: stable@vger.kernel.org Signed-off-by: Andreas Gruenbacher Reviewed-by: Jan Kara Signed-off-by: Al Viro Signed-off-by: Willy Tarreau --- fs/direct-io.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/direct-io.c b/fs/direct-io.c index e17d919..85485c1 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -760,6 +760,8 @@ 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; } -- 2.8.0.rc2.1.gbe9624a