From patchwork Fri Jul 26 15:41:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 262200 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 720DD2C00B6 for ; Sat, 27 Jul 2013 01:54:45 +1000 (EST) Received: from localhost ([::1]:51026 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2kLr-0004Qr-0A for incoming@patchwork.ozlabs.org; Fri, 26 Jul 2013 11:54:43 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35955) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2kLV-0004KC-3L for qemu-devel@nongnu.org; Fri, 26 Jul 2013 11:54:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V2kLS-0003QX-OM for qemu-devel@nongnu.org; Fri, 26 Jul 2013 11:54:21 -0400 Received: from 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.d.1.0.0.b.8.0.1.0.0.2.ip6.arpa ([2001:8b0:1d0::1]:58984 helo=mnementh.archaic.org.uk) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2kLS-0003QT-HW for qemu-devel@nongnu.org; Fri, 26 Jul 2013 11:54:18 -0400 Received: from pm215 by mnementh.archaic.org.uk with local (Exim 4.80) (envelope-from ) id 1V2k92-0002aP-UX; Fri, 26 Jul 2013 16:41:29 +0100 From: Peter Maydell To: qemu-devel@nongnu.org Date: Fri, 26 Jul 2013 16:41:27 +0100 Message-Id: <1374853288-9912-2-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1374853288-9912-1-git-send-email-peter.maydell@linaro.org> References: <1374853288-9912-1-git-send-email-peter.maydell@linaro.org> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2001:8b0:1d0::1 Cc: KONRAD Frederic , Anthony Liguori , "Michael S. Tsirkin" , kvmarm@lists.cs.columbia.edu, patches@linaro.org Subject: [Qemu-devel] [PATCH v2 for-1.6 1/2] hw/virtio/virtio: Don't allow guests to add/remove queues 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 A queue size of 0 is used to indicate a nonexistent queue, so don't allow the guest to flip a queue between zero-size and non-zero-size. Don't permit setting of negative queue sizes either. Signed-off-by: Peter Maydell Reviewed-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 09f62c6..60653f7 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -673,10 +673,16 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) { - if (num <= VIRTQUEUE_MAX_SIZE) { - vdev->vq[n].vring.num = num; - virtqueue_init(&vdev->vq[n]); + /* Don't allow guest to flip queue between existent and + * nonexistent states, or to set it to an invalid size. + */ + if (!!num != !!vdev->vq[n].vring.num || + num > VIRTQUEUE_MAX_SIZE || + num < 0) { + return; } + vdev->vq[n].vring.num = num; + virtqueue_init(&vdev->vq[n]); } int virtio_queue_get_num(VirtIODevice *vdev, int n)