From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C97E9C433E1 for ; Mon, 17 Aug 2020 18:31:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A11F22053B for ; Mon, 17 Aug 2020 18:31:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597689084; bh=aYbZFZAHTLy3UcV8xwsyYILmR4yEHjaWIROYwmwIX6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xYNXvTS+tOpIUfxVmnd1VgXwTZLaFGA83vH97gP6Dx+UDWkk1//FFrkAq+91REXsE 1Jj40pZgreuZFZNflIXcfmhwpbdBRoLW5mbcRI5X19djNz1emN5UvilBmLpAR0t0Iw dFf65ZHvE/HrX9gyl6vQcfledFEmnSVXJLtaCFQk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388811AbgHQSbV (ORCPT ); Mon, 17 Aug 2020 14:31:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:48590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387969AbgHQQBS (ORCPT ); Mon, 17 Aug 2020 12:01:18 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0C0C020772; Mon, 17 Aug 2020 16:01:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597680069; bh=aYbZFZAHTLy3UcV8xwsyYILmR4yEHjaWIROYwmwIX6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OcP8JhHo0VjtEi1NHIuI1IlT+xu0H6NqX9pN+T5yIcYUUy7zaTl8h7KtPDqMNXxau 0J3lAQolhzpvOGhrtseTpuO20j/QXU50dLkjr8zj4Hi1S25WqbXEh8DU/hF03DnwR9 J7jXZalO2JXFrEbti2akoMHx55sSsfa3nFlgk7hU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , "Guilherme G. Piccoli" , Song Liu , Sasha Levin Subject: [PATCH 5.4 041/270] md: raid0/linear: fix dereference before null check on pointer mddev Date: Mon, 17 Aug 2020 17:14:02 +0200 Message-Id: <20200817143757.858028322@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143755.807583758@linuxfoundation.org> References: <20200817143755.807583758@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin Ian King [ Upstream commit 9a5a85972c073f720d81a7ebd08bfe278e6e16db ] Pointer mddev is being dereferenced with a test_bit call before mddev is being null checked, this may cause a null pointer dereference. Fix this by moving the null pointer checks to sanity check mddev before it is dereferenced. Addresses-Coverity: ("Dereference before null check") Fixes: 62f7b1989c02 ("md raid0/linear: Mark array as 'broken' and fail BIOs if a member is gone") Signed-off-by: Colin Ian King Reviewed-by: Guilherme G. Piccoli Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/md.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 5a378a453a2d4..acef01e519d06 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -376,17 +376,18 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio) struct mddev *mddev = q->queuedata; unsigned int sectors; - if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) { + if (mddev == NULL || mddev->pers == NULL) { bio_io_error(bio); return BLK_QC_T_NONE; } - blk_queue_split(q, &bio); - - if (mddev == NULL || mddev->pers == NULL) { + if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) { bio_io_error(bio); return BLK_QC_T_NONE; } + + blk_queue_split(q, &bio); + if (mddev->ro == 1 && unlikely(rw == WRITE)) { if (bio_sectors(bio) != 0) bio->bi_status = BLK_STS_IOERR; -- 2.25.1