From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49658) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMfCZ-0000qB-LI for qemu-devel@nongnu.org; Wed, 06 Dec 2017 14:17:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eMfCW-0000r3-H3 for qemu-devel@nongnu.org; Wed, 06 Dec 2017 14:17:51 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48732 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eMfCW-0000qS-AQ for qemu-devel@nongnu.org; Wed, 06 Dec 2017 14:17:48 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vB6JEsEi037203 for ; Wed, 6 Dec 2017 14:17:47 -0500 Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) by mx0a-001b2d01.pphosted.com with ESMTP id 2eppat0mfp-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 06 Dec 2017 14:17:47 -0500 Received: from localhost by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Dec 2017 12:17:46 -0700 From: Michael Roth Date: Wed, 6 Dec 2017 13:15:56 -0600 In-Reply-To: <20171206191648.18208-1-mdroth@linux.vnet.ibm.com> References: <20171206191648.18208-1-mdroth@linux.vnet.ibm.com> Message-Id: <20171206191648.18208-4-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 03/55] block/mirror: check backing in bdrv_mirror_top_flush List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Vladimir Sementsov-Ogievskiy , Max Reitz From: Vladimir Sementsov-Ogievskiy Backing may be zero after failed bdrv_append in mirror_start_job, which leads to SIGSEGV. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-id: 20170929152255.5431-1-vsementsov@virtuozzo.com Signed-off-by: Max Reitz (cherry picked from commit ce960aa9062a407d0ca15aee3dcd3bd84a4e24f9) Signed-off-by: Michael Roth --- block/mirror.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/mirror.c b/block/mirror.c index 429751b9fe..03fc6d63b7 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1056,6 +1056,10 @@ static int coroutine_fn bdrv_mirror_top_pwritev(BlockDriverState *bs, static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs) { + if (bs->backing == NULL) { + /* we can be here after failed bdrv_append in mirror_start_job */ + return 0; + } return bdrv_co_flush(bs->backing->bs); } -- 2.11.0