Commit 9e0f5b81 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio: validate the existence of handle_output before calling it 



We don't validate the existence of handle_output which may let a buggy
guest to trigger a SIGSEV easily. E.g:

1) write 10 to queue_sel to a virtio net device with only 1 queue
2) setup an arbitrary pfn
3) then notify queue 10

Fixing this by validating the existence of handle_output before.

Cc: qemu-stable@nongnu.org
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarDon Koch <dkoch@verizon.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
parent 18bf9e2f

hw/virtio/virtio.c

+2 −1
Original line number Diff line number Diff line
@@ -759,8 +759,9 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) 


void virtio_queue_notify_vq(VirtQueue *vq)

{

    if (vq->vring.desc) {

    if (vq->vring.desc && vq->handle_output) {

        VirtIODevice *vdev = vq->vdev;



        trace_virtio_queue_notify(vdev, vq - vdev->vq, vq);

        vq->handle_output(vdev, vq);

    }