From patchwork Fri Jul 14 10:00:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9840415 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E74A1602D8 for ; Fri, 14 Jul 2017 10:02:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D928F28748 for ; Fri, 14 Jul 2017 10:02:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CE11828770; Fri, 14 Jul 2017 10:02:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B10E62876E for ; Fri, 14 Jul 2017 10:02:08 +0000 (UTC) Received: from localhost ([::1]:36650 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dVxQF-0007dG-VX for patchwork-qemu-devel@patchwork.kernel.org; Fri, 14 Jul 2017 06:02:08 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39623) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dVxOy-0007bb-OW for qemu-devel@nongnu.org; Fri, 14 Jul 2017 06:00:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dVxOy-0000uI-3I for qemu-devel@nongnu.org; Fri, 14 Jul 2017 06:00:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44946) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dVxOs-0000sG-8l; Fri, 14 Jul 2017 06:00:42 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3D99491C36; Fri, 14 Jul 2017 10:00:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 3D99491C36 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=ppandit@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 3D99491C36 Received: from localhost.localdomain (ovpn-116-54.ams2.redhat.com [10.36.116.54]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4D74A6FAB6; Fri, 14 Jul 2017 10:00:34 +0000 (UTC) From: P J P To: Qemu Developers Date: Fri, 14 Jul 2017 15:30:29 +0530 Message-Id: <20170714100029.26288-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 14 Jul 2017 10:00:40 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] ide: check BlockBackend object in ide_cancel_dma_sync X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: John Snow , Chensongnian , qemu-block@nongnu.org, Prasad J Pandit Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit When cancelling pending DMA requests in ide_cancel_dma_sync, the s->blk object could be null, leading to a null dereference. Add check to avoid it. Reported-by: Chensongnian Signed-off-by: Prasad J Pandit --- hw/ide/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/hw/ide/core.c b/hw/ide/core.c index 0b48b64..04474b3 100644 --- a/hw/ide/core.c +++ b/hw/ide/core.c @@ -681,8 +681,10 @@ void ide_cancel_dma_sync(IDEState *s) #ifdef DEBUG_IDE printf("%s: draining all remaining requests", __func__); #endif - blk_drain(s->blk); - assert(s->bus->dma->aiocb == NULL); + if (s->blk) { + blk_drain(s->blk); + assert(s->bus->dma->aiocb == NULL); + } } }