Virtualization - Jul 2021 - [PATCH 1/2] vhost-vdpa: Fix integer overflow in vhost_vdpa_process_iotlb_update()

? 2021/7/16 ??6:22, Xie Yongji ??:
> The "msg->iova + msg->size" addition can have an integer
overflow
> if the iotlb message is from a malicious user space application.
> So let's fix it.
>
> Fixes: 1b48dc03e575 ("vhost: vdpa: report iova range")
> Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
> Signed-off-by: Xie Yongji <xieyongji at bytedance.com>

Acked-by: Jason Wang <jasowang at redhat.com>

> ---
>   drivers/vhost/vdpa.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 210ab35a7ebf..8e3c8790d493 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -615,6 +615,7 @@ static int vhost_vdpa_process_iotlb_update(struct
vhost_vdpa *v,
>   	int ret = 0;
>   
>   	if (msg->iova < v->range.first ||
> +	    msg->iova - 1 > U64_MAX - msg->size ||
>   	    msg->iova + msg->size - 1 > v->range.last)
>   		return -EINVAL;
>