From nobody Thu May 16 12:32:47 2024 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; dkim=fail; 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 (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 151338608259180.99981257294905; Fri, 15 Dec 2017 17:01:22 -0800 (PST) Received: from localhost ([::1]:48993 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eQ0ql-0001eI-9X for importer@patchew.org; Fri, 15 Dec 2017 20:01:11 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44954) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eQ0pq-0001JL-Os for qemu-devel@nongnu.org; Fri, 15 Dec 2017 20:00:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eQ0pp-0007bx-1Y for qemu-devel@nongnu.org; Fri, 15 Dec 2017 20:00:14 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:52860) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eQ0pi-0007SC-DV; Fri, 15 Dec 2017 20:00:06 -0500 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.21/8.16.0.21) with SMTP id vBG103v1121524; Sat, 16 Dec 2017 01:00:04 GMT Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by aserp2130.oracle.com with ESMTP id 2evsej800g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 16 Dec 2017 01:00:03 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id vBG102x4004901 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Sat, 16 Dec 2017 01:00:03 GMT Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id vBG102XB007138; Sat, 16 Dec 2017 01:00:02 GMT Received: from deepas-x1.oracle.com (/10.197.191.193) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 15 Dec 2017 16:59:31 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=mime-version : message-id : date : from : to : cc : subject : content-type : content-transfer-encoding; s=corp-2017-10-26; bh=nddqOH31GJGkmDwWMAWSne8zsX00eRsePLK1C7O00Vk=; b=sDg6XL79b/RndrdQCQooBxEaH+DUJi9RNv9PKYIR58OuheYc5LH4cbJokSptI5IfMn3V +U3X5emtDcWFKiaP27HUcwGPaSMQrQ2dPeZ+Hi+IoI1YNxn38i1EMxlcI8+MOOzGUFXT 8YoBh30IX81lW/f7m9KOc4Y9X3Any4VALo3oRkbvhVPy25ui/JAmCxgYTQKGT+crnsJP Sig2W5FecG+yODQ8uVZ/T/4Xes9AAos3to1pQ78osRtZnssF9bDfykSzOtPqYrmzt7yq /HNCzolMBhvcpGfPN0iCJvPXZDBkP6vHOnS47AuNL2r7SpkvftiOtiE4+zkzm4vtuKJ/ iQ== MIME-Version: 1.0 Message-ID: <1513385953-5466-1-git-send-email-deepa.srinivasan@oracle.com> Date: Fri, 15 Dec 2017 16:59:13 -0800 (PST) From: Deepa Srinivasan To: deepa.srinivasan@oracle.com, kwolf@redhat.com, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, qemu-block@nongnu.org, qemu-devel@nongnu.org, mark.kanda@oracle.com X-Mailer: git-send-email 2.7.4 Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8746 signatures=668648 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1712160012 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 141.146.126.79 Subject: [Qemu-devel] [PATCH v2] block: Fix qemu crash when using scsi-block 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: Konrad Rzeszutek Wilk Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" Starting qemu with the following arguments causes qemu to segfault: ... -device lsi,id=3Dlsi0 -drive file=3Discsi:<...>,format=3Draw,if=3Dnone,= node-name=3D iscsi1 -device scsi-block,bus=3Dlsi0.0,id=3D<...>,drive=3Discsi1 This patch fixes blk_aio_ioctl() so it does not pass stack addresses to blk_aio_ioctl_entry() which may be invoked after blk_aio_ioctl() returns. M= ore details about the bug follow. blk_aio_ioctl() invokes blk_aio_prwv() with blk_aio_ioctl_entry as the coroutine parameter. blk_aio_prwv() ultimately calls aio_co_enter(). When blk_aio_ioctl() is executed from within a coroutine context (e.g. iscsi_bh_cb()), aio_co_enter() adds the coroutine (blk_aio_ioctl_entry) to the current coroutine's wakeup queue. blk_aio_ioctl() then returns. When blk_aio_ioctl_entry() executes later, it accesses an invalid pointer: .... BlkRwCo *rwco =3D &acb->rwco; rwco->ret =3D blk_co_ioctl(rwco->blk, rwco->offset, rwco->qiov->iov[0].iov_base); <--- qiov is invalid he= re ... In the case when blk_aio_ioctl() is called from a non-coroutine context, blk_aio_ioctl_entry() executes immediately. But if bdrv_co_ioctl() calls qemu_coroutine_yield(), blk_aio_ioctl() will return. When the coroutine execution is complete, control returns to blk_aio_ioctl_entry() after the c= all to blk_co_ioctl(). There is no invalid reference after this point, but the function is still holding on to invalid pointers. The fix is to change blk_aio_prwv() to accept a void pointer for the IO buf= fer rather than a QEMUIOVector. blk_aio_prwv() passes this through in BlkRwCo a= nd the coroutine function casts it to QEMUIOVector or uses the void pointer direct= ly. Signed-off-by: Deepa Srinivasan Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Mark Kanda Reviewed-by: Paolo Bonzini Reviewed-by: Stefan Hajnoczi --- block/block-backend.c | 51 +++++++++++++++++++++++++----------------------= ---- 1 file changed, 25 insertions(+), 26 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index baef8e7..2d0d9b6 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1140,7 +1140,7 @@ int coroutine_fn blk_co_pwritev(BlockBackend *blk, in= t64_t offset, typedef struct BlkRwCo { BlockBackend *blk; int64_t offset; - QEMUIOVector *qiov; + void *iobuf; int ret; BdrvRequestFlags flags; } BlkRwCo; @@ -1148,17 +1148,19 @@ typedef struct BlkRwCo { static void blk_read_entry(void *opaque) { BlkRwCo *rwco =3D opaque; + QEMUIOVector *qiov =3D rwco->iobuf; =20 - rwco->ret =3D blk_co_preadv(rwco->blk, rwco->offset, rwco->qiov->size, - rwco->qiov, rwco->flags); + rwco->ret =3D blk_co_preadv(rwco->blk, rwco->offset, qiov->size, + qiov, rwco->flags); } =20 static void blk_write_entry(void *opaque) { BlkRwCo *rwco =3D opaque; + QEMUIOVector *qiov =3D rwco->iobuf; =20 - rwco->ret =3D blk_co_pwritev(rwco->blk, rwco->offset, rwco->qiov->size, - rwco->qiov, rwco->flags); + rwco->ret =3D blk_co_pwritev(rwco->blk, rwco->offset, qiov->size, + qiov, rwco->flags); } =20 static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, @@ -1178,7 +1180,7 @@ static int blk_prw(BlockBackend *blk, int64_t offset,= uint8_t *buf, rwco =3D (BlkRwCo) { .blk =3D blk, .offset =3D offset, - .qiov =3D &qiov, + .iobuf =3D &qiov, .flags =3D flags, .ret =3D NOT_DONE, }; @@ -1275,7 +1277,7 @@ static void blk_aio_complete_bh(void *opaque) } =20 static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int byt= es, - QEMUIOVector *qiov, CoroutineEntry co_entr= y, + void *iobuf, CoroutineEntry co_entry, BdrvRequestFlags flags, BlockCompletionFunc *cb, void *opaque) { @@ -1287,7 +1289,7 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, in= t64_t offset, int bytes, acb->rwco =3D (BlkRwCo) { .blk =3D blk, .offset =3D offset, - .qiov =3D qiov, + .iobuf =3D iobuf, .flags =3D flags, .ret =3D NOT_DONE, }; @@ -1310,10 +1312,11 @@ static void blk_aio_read_entry(void *opaque) { BlkAioEmAIOCB *acb =3D opaque; BlkRwCo *rwco =3D &acb->rwco; + QEMUIOVector *qiov =3D rwco->iobuf; =20 - assert(rwco->qiov->size =3D=3D acb->bytes); + assert(qiov->size =3D=3D acb->bytes); rwco->ret =3D blk_co_preadv(rwco->blk, rwco->offset, acb->bytes, - rwco->qiov, rwco->flags); + qiov, rwco->flags); blk_aio_complete(acb); } =20 @@ -1321,10 +1324,11 @@ static void blk_aio_write_entry(void *opaque) { BlkAioEmAIOCB *acb =3D opaque; BlkRwCo *rwco =3D &acb->rwco; + QEMUIOVector *qiov =3D rwco->iobuf; =20 - assert(!rwco->qiov || rwco->qiov->size =3D=3D acb->bytes); + assert(!qiov || qiov->size =3D=3D acb->bytes); rwco->ret =3D blk_co_pwritev(rwco->blk, rwco->offset, acb->bytes, - rwco->qiov, rwco->flags); + qiov, rwco->flags); blk_aio_complete(acb); } =20 @@ -1453,8 +1457,10 @@ int blk_co_ioctl(BlockBackend *blk, unsigned long in= t req, void *buf) static void blk_ioctl_entry(void *opaque) { BlkRwCo *rwco =3D opaque; + QEMUIOVector *qiov =3D rwco->iobuf; + rwco->ret =3D blk_co_ioctl(rwco->blk, rwco->offset, - rwco->qiov->iov[0].iov_base); + qiov->iov[0].iov_base); } =20 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf) @@ -1467,24 +1473,15 @@ static void blk_aio_ioctl_entry(void *opaque) BlkAioEmAIOCB *acb =3D opaque; BlkRwCo *rwco =3D &acb->rwco; =20 - rwco->ret =3D blk_co_ioctl(rwco->blk, rwco->offset, - rwco->qiov->iov[0].iov_base); + rwco->ret =3D blk_co_ioctl(rwco->blk, rwco->offset, rwco->iobuf); + blk_aio_complete(acb); } =20 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *= buf, BlockCompletionFunc *cb, void *opaque) { - QEMUIOVector qiov; - struct iovec iov; - - iov =3D (struct iovec) { - .iov_base =3D buf, - .iov_len =3D 0, - }; - qemu_iovec_init_external(&qiov, &iov, 1); - - return blk_aio_prwv(blk, req, 0, &qiov, blk_aio_ioctl_entry, 0, cb, op= aque); + return blk_aio_prwv(blk, req, 0, buf, blk_aio_ioctl_entry, 0, cb, opaq= ue); } =20 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes) @@ -1900,7 +1897,9 @@ int blk_truncate(BlockBackend *blk, int64_t offset, P= reallocMode prealloc, static void blk_pdiscard_entry(void *opaque) { BlkRwCo *rwco =3D opaque; - rwco->ret =3D blk_co_pdiscard(rwco->blk, rwco->offset, rwco->qiov->siz= e); + QEMUIOVector *qiov =3D rwco->iobuf; + + rwco->ret =3D blk_co_pdiscard(rwco->blk, rwco->offset, qiov->size); } =20 int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes) --=20 2.7.4