From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44310) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VnuXn-0001n7-Fw for qemu-devel@nongnu.org; Tue, 03 Dec 2013 13:18:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VnuXg-00041M-VJ for qemu-devel@nongnu.org; Tue, 03 Dec 2013 13:17:59 -0500 Date: Tue, 3 Dec 2013 18:28:33 +0200 From: "Michael S. Tsirkin" Message-ID: <1386087086-3691-5-git-send-email-mst@redhat.com> References: <1386087086-3691-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1386087086-3691-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PATCH 04/23] virtio: out-of-bounds buffer write on invalid state load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Anthony Liguori , Michael Roth CVE-2013-4151 QEMU 1.0 out-of-bounds buffer write in virtio_load@hw/virtio/virtio.c So we have this code since way back when: num = qemu_get_be32(f); for (i = 0; i < num; i++) { vdev->vq[i].vring.num = qemu_get_be32(f); array of vqs has size VIRTIO_PCI_QUEUE_MAX, so on invalid input this will write beyond end of buffer. Signed-off-by: Michael S. Tsirkin Reviewed-by: Michael Roth --- hw/virtio/virtio.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 2f1e73b..ec23cb5 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -888,7 +888,8 @@ int virtio_set_features(VirtIODevice *vdev, uint32_t val) int virtio_load(VirtIODevice *vdev, QEMUFile *f) { - int num, i, ret; + int i, ret; + uint32_t num; uint32_t features; uint32_t supported_features; BusState *qbus = qdev_get_parent_bus(DEVICE(vdev)); @@ -916,6 +917,11 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f) num = qemu_get_be32(f); + if (num > VIRTIO_PCI_QUEUE_MAX) { + error_report("Invalid number of PCI queues: 0x%x", num); + return -1; + } + for (i = 0; i < num; i++) { vdev->vq[i].vring.num = qemu_get_be32(f); if (k->has_variable_vring_alignment) { -- MST