From nobody Tue Feb 10 04:29:42 2026 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 151197762625685.70948820162789; Wed, 29 Nov 2017 09:47:06 -0800 (PST) Received: from localhost ([::1]:44406 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eK6Rm-0005wa-H4 for importer@patchew.org; Wed, 29 Nov 2017 12:46:58 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59206) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eK6Pc-0004Tf-NP for qemu-devel@nongnu.org; Wed, 29 Nov 2017 12:44:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eK6Pa-0001XG-RE for qemu-devel@nongnu.org; Wed, 29 Nov 2017 12:44:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33590) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eK6Pa-0001Wj-LI for qemu-devel@nongnu.org; Wed, 29 Nov 2017 12:44:42 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C60A461476; Wed, 29 Nov 2017 17:44:41 +0000 (UTC) Received: from localhost.localdomain (ovpn-116-55.ams2.redhat.com [10.36.116.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E2CD260560; Wed, 29 Nov 2017 17:44:38 +0000 (UTC) From: P J P To: Qemu Developers Date: Wed, 29 Nov 2017 23:14:27 +0530 Message-Id: <20171129174428.27548-2-ppandit@redhat.com> In-Reply-To: <20171129174428.27548-1-ppandit@redhat.com> References: <20171129174428.27548-1-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 29 Nov 2017 17:44:41 +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 v4 1/2] virtio: check VirtQueue Vring object is set 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: Paolo Bonzini , Cornelia Huck , zhangboxian , Stefan Hajnoczi , Prasad J Pandit 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: Prasad J Pandit A guest could attempt to use an uninitialised VirtQueue object or unset Vring.align leading to a arithmetic exception. Add check to avoid it. Reported-by: Zhangboxian Signed-off-by: Prasad J Pandit Reviewed-by: Cornelia Huck --- hw/virtio/virtio.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) Update: removed !desc and !vring.align check from virtio_queue_set_rings -> https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg04809.html diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 5884ce3480..a0d2c887cc 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -182,7 +182,7 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int = n) { VRing *vring =3D &vdev->vq[n].vring; =20 - if (!vring->desc) { + if (!vring->num || !vring->desc || !vring->align) { /* not yet setup -> nothing to do */ return; } @@ -1414,6 +1414,9 @@ void virtio_config_modern_writel(VirtIODevice *vdev, =20 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr) { + if (!vdev->vq[n].vring.num) { + return; + } vdev->vq[n].vring.desc =3D addr; virtio_queue_update_rings(vdev, n); } @@ -1426,6 +1429,9 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int = n) void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, hwaddr avail, hwaddr used) { + if (!vdev->vq[n].vring.num) { + return; + } vdev->vq[n].vring.desc =3D desc; vdev->vq[n].vring.avail =3D avail; vdev->vq[n].vring.used =3D used; @@ -1494,8 +1500,10 @@ void virtio_queue_set_align(VirtIODevice *vdev, int = n, int align) */ assert(k->has_variable_vring_alignment); =20 - vdev->vq[n].vring.align =3D align; - virtio_queue_update_rings(vdev, n); + if (align) { + vdev->vq[n].vring.align =3D align; + virtio_queue_update_rings(vdev, n); + } } =20 static bool virtio_queue_notify_aio_vq(VirtQueue *vq) --=20 2.13.6