vhost: do not try to access device IOTLB when not initialized

The code will try to access dev->iotlb when processing
VHOST_IOTLB_INVALIDATE even if it was not initialized which may lead
to NULL pointer dereference. Fixes this by check dev->iotlb before.

Fixes: 6b1e6cc785 ("vhost: new device IOTLB API")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2018-01-23 17:27:26 +08:00 committed by David S. Miller
parent e9cb423913
commit 6f3180afbb

View File

@ -1015,6 +1015,10 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
vhost_iotlb_notify_vq(dev, msg);
break;
case VHOST_IOTLB_INVALIDATE:
if (!dev->iotlb) {
ret = -EFAULT;
break;
}
vhost_vq_meta_reset(dev);
vhost_del_umem_range(dev->iotlb, msg->iova,
msg->iova + msg->size - 1);