From 9dfb93fc21a678858e95e604339d95829f405724 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Wed, 14 May 2014 08:31:53 +0200 Subject: [PATCH 12/31] virtio: out-of-bounds buffer write on invalid state load RH-Author: Michael S. Tsirkin Message-id: <1400056285-6688-4-git-send-email-mst@redhat.com> Patchwork-id: 58858 O-Subject: [PATCH qemu-kvm RHEL7.1] virtio: out-of-bounds buffer write on invalid state load Bugzilla: 1095695 RH-Acked-by: Dr. David Alan Gilbert (git) RH-Acked-by: Juan Quintela RH-Acked-by: Xiao Wang 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 Signed-off-by: Juan Quintela (cherry picked from commit cc45995294b92d95319b4782750a3580cabdbc0c) Tested: lightly on developer's box Brew build: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=7452039 Bugzilla: 1095695 --- hw/virtio/virtio.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) Signed-off-by: Miroslav Rezanina --- hw/virtio/virtio.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index b5bb0b6..070d64e 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -851,7 +851,8 @@ 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)); @@ -879,6 +880,11 @@ 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); vdev->vq[i].pa = qemu_get_be64(f); -- 1.7.1