virtio: avoid buffer overrun on incoming migration

CVE-2013-6399

vdev->queue_sel is read from the wire, and later used in the
emulation code as an index into vdev->vq[]. If the value of
vdev->queue_sel exceeds the length of vdev->vq[], currently
allocated to be VIRTIO_PCI_QUEUE_MAX elements, subsequent PIO
operations such as VIRTIO_PCI_QUEUE_PFN can be used to overrun
the buffer with arbitrary data originating from the source.

Fix this by failing migration if the value from the wire exceeds
VIRTIO_PCI_QUEUE_MAX.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Michael Roth 2014-04-03 19:51:46 +03:00 committed by Juan Quintela
parent d2ef4b61fe
commit 4b53c2c72c
1 changed files with 3 additions and 0 deletions

View File

@ -907,6 +907,9 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
qemu_get_8s(f, &vdev->status);
qemu_get_8s(f, &vdev->isr);
qemu_get_be16s(f, &vdev->queue_sel);
if (vdev->queue_sel >= VIRTIO_PCI_QUEUE_MAX) {
return -1;
}
qemu_get_be32s(f, &features);
if (virtio_set_features(vdev, features) < 0) {