From patchwork Mon Jul 11 13:55:42 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 104215 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id D1D8DB6F7C for ; Tue, 12 Jul 2011 00:12:48 +1000 (EST) Received: from localhost ([::1]:37804 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QgHE5-000547-EV for incoming@patchwork.ozlabs.org; Mon, 11 Jul 2011 10:12:45 -0400 Received: from eggs.gnu.org ([140.186.70.92]:53313) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QgGxF-0001dR-VK for qemu-devel@nongnu.org; Mon, 11 Jul 2011 09:55:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QgGxE-0006Zr-Ja for qemu-devel@nongnu.org; Mon, 11 Jul 2011 09:55:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57377) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QgGxE-0006Zi-57 for qemu-devel@nongnu.org; Mon, 11 Jul 2011 09:55:20 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p6BDtIlD015225 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 11 Jul 2011 09:55:18 -0400 Received: from redhat.com (vpn-203-16.tlv.redhat.com [10.35.203.16]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id p6BDtFY1002598; Mon, 11 Jul 2011 09:55:16 -0400 Date: Mon, 11 Jul 2011 16:55:42 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20110711135542.GA23769@redhat.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: Anthony Liguori Subject: [Qemu-devel] [PATCH] virtio: fix indirect descriptor buffer overflow X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org We were previously allowing arbitrarily-long indirect descriptors, which could lead to a buffer overflow in qemu-kvm process. CVE-2011-2212 Signed-off-by: Michael S. Tsirkin --- hw/virtio.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/hw/virtio.c b/hw/virtio.c index e6043de..8a6f38c 100644 --- a/hw/virtio.c +++ b/hw/virtio.c @@ -449,9 +449,17 @@ int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem) struct iovec *sg; if (vring_desc_flags(desc_pa, i) & VRING_DESC_F_WRITE) { + if (elem->in_num >= ARRAY_SIZE(elem->in_sg)) { + error_report("Too many write descriptors in indirect table"); + exit(1); + } elem->in_addr[elem->in_num] = vring_desc_addr(desc_pa, i); sg = &elem->in_sg[elem->in_num++]; } else { + if (elem->out_num >= ARRAY_SIZE(elem->out_sg)) { + error_report("Too many read descriptors in indirect table"); + exit(1); + } elem->out_addr[elem->out_num] = vring_desc_addr(desc_pa, i); sg = &elem->out_sg[elem->out_num++]; }