On Tue, Jan 23, 2018 at 05:27:26PM +0800, Jason Wang wrote:
> 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: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
> Signed-off-by: Jason Wang <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
> ---
> drivers/vhost/vhost.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 549771a..5727b18 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -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);
> --
> 2.7.4
