From nobody Tue Nov 4 15:43:12 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1503968537529753.1311913169711; Mon, 28 Aug 2017 18:02:17 -0700 (PDT) Received: from localhost ([::1]:42147 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmUv1-0000KA-Kn for importer@patchew.org; Mon, 28 Aug 2017 21:02:15 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48241) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dmUCZ-0001PX-9o for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:16:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dmUCW-0005cX-0Z for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:16:19 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49574) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dmUCV-0005ZP-LV for qemu-devel@nongnu.org; Mon, 28 Aug 2017 20:16:15 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7T0FxG6009445 for ; Mon, 28 Aug 2017 20:16:14 -0400 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cmvjejkke-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 28 Aug 2017 20:16:14 -0400 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 28 Aug 2017 18:16:11 -0600 Received: from b03ledav001.gho.boulder.ibm.com (b03ledav001.gho.boulder.ibm.com [9.17.130.232]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v7T0GAhC7733724; Mon, 28 Aug 2017 17:16:10 -0700 Received: from b03ledav001.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 816766E038; Mon, 28 Aug 2017 18:16:10 -0600 (MDT) Received: from localhost (unknown [9.80.85.217]) by b03ledav001.gho.boulder.ibm.com (Postfix) with ESMTP id 4EE596E041; Mon, 28 Aug 2017 18:16:10 -0600 (MDT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 28 Aug 2017 19:14:20 -0500 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1503965694-10794-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1503965694-10794-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17082900-0028-0000-0000-00000846DB3A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007630; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000226; SDB=6.00909028; UDB=6.00455849; IPR=6.00689279; BA=6.00005557; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016909; XFM=3.00000015; UTC=2017-08-29 00:16:12 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17082900-0029-0000-0000-000037553151 Message-Id: <1503965694-10794-46-git-send-email-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-08-28_13:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1708290001 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 45/79] block: Guarantee that *file is set on bdrv_get_block_status() 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: Kevin Wolf , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Eric Blake We document that *file is valid if the return is not an error and includes BDRV_BLOCK_OFFSET_VALID, but forgot to obey this contract when a driver (such as blkdebug) lacks a callback. Messed up in commit 67a0fd2 (v2.6), when we added the file parameter. Enhance qemu-iotest 177 to cover this, using a sequence that would print garbage or even SEGV, because it was dererefencing through uninitialized memory. [The resulting test output shows that we have less-than-ideal block status from the blkdebug driver, but that's a separate fix coming up soon.] Setting *file on all paths that return BDRV_BLOCK_OFFSET_VALID is enough to fix the crash, but we can go one step further: always setting *file, even on error, means that a broken caller that blindly dereferences file without checking for error is now more likely to get a reliable SEGV instead of randomly acting on garbage, making it easier to diagnose such buggy callers. Adding an assertion that file is set where expected doesn't hurt either. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake Reviewed-by: Fam Zheng Reviewed-by: Max Reitz Reviewed-by: John Snow Signed-off-by: Kevin Wolf (cherry picked from commit 81c219ac6ce0d6182e35f3976f2caa4cefcaf9f0) Signed-off-by: Michael Roth --- block/io.c | 5 +++-- tests/qemu-iotests/177 | 3 +++ tests/qemu-iotests/177.out | 2 ++ 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index fe0c867..a8589ee 100644 --- a/block/io.c +++ b/block/io.c @@ -1757,6 +1757,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(= BlockDriverState *bs, int64_t n; int64_t ret, ret2; =20 + *file =3D NULL; total_sectors =3D bdrv_nb_sectors(bs); if (total_sectors < 0) { return total_sectors; @@ -1777,11 +1778,11 @@ static int64_t coroutine_fn bdrv_co_get_block_statu= s(BlockDriverState *bs, ret =3D BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; if (bs->drv->protocol_name) { ret |=3D BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_S= IZE); + *file =3D bs; } return ret; } =20 - *file =3D NULL; bdrv_inc_in_flight(bs); ret =3D bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, = pnum, file); @@ -1791,7 +1792,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(= BlockDriverState *bs, } =20 if (ret & BDRV_BLOCK_RAW) { - assert(ret & BDRV_BLOCK_OFFSET_VALID); + assert(ret & BDRV_BLOCK_OFFSET_VALID && *file); ret =3D bdrv_co_get_block_status(*file, ret >> BDRV_SECTOR_BITS, *pnum, pnum, file); goto out; diff --git a/tests/qemu-iotests/177 b/tests/qemu-iotests/177 index 2005c17..f8ed8fb 100755 --- a/tests/qemu-iotests/177 +++ b/tests/qemu-iotests/177 @@ -43,6 +43,7 @@ _supported_proto file CLUSTER_SIZE=3D1M size=3D128M options=3Ddriver=3Dblkdebug,image.driver=3Dqcow2 +nested_opts=3Dimage.file.driver=3Dfile,image.file.filename=3D$TEST_IMG =20 echo echo "=3D=3D setting up files =3D=3D" @@ -106,6 +107,8 @@ function verify_io() } =20 verify_io | $QEMU_IO -r "$TEST_IMG" | _filter_qemu_io +$QEMU_IMG map --image-opts "$options,$nested_opts,align=3D4k" \ + | _filter_qemu_img_map =20 _check_test_img =20 diff --git a/tests/qemu-iotests/177.out b/tests/qemu-iotests/177.out index e887542..fcfbfa3 100644 --- a/tests/qemu-iotests/177.out +++ b/tests/qemu-iotests/177.out @@ -45,5 +45,7 @@ read 30408704/30408704 bytes at offset 80740352 29 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) read 23068672/23068672 bytes at offset 111149056 22 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +Offset Length File +0 0x8000000 json:{"image": {"driver": "IMGFMT", "file"= : {"driver": "file", "filename": "TEST_DIR/t.IMGFMT"}}, "driver": "blkdebug= ", "align": "4k"} No errors were found on the image. *** done --=20 2.7.4