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-sta...@nongnu.org
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
Changes from V1:
- check the existence of both vring.desc and handle_output in the same
line
- describe the reproducer in the commit log
---
hw/virtio/virtio.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 3c6e430..17c1260 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -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);
}
--
2.1.0
