virtio_vdpa: reject invalid vq indices

[ Upstream commit cb5d2c1 ]

Do not call vDPA drivers' callbacks with vq indicies larger than what
the drivers indicate that they support.  vDPA drivers do not bounds
check the indices.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20210701114652.21956-1-vincent.whitchurch@axis.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/virtio/virtio_vdpa.c

@@ -149,6 +149,9 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index,
 	if (!name)
 		return NULL;
 
+	if (index >= vdpa->nvqs)
+		return ERR_PTR(-ENOENT);
+
 	/* Queue shouldn't already be set up. */
 	if (ops->get_vq_ready(vdpa, index))
 		return ERR_PTR(-ENOENT);