Re: [Xen-devel] [PATCH 4/6] xen-netfront: add range check for Tx response id

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Mon, Apr 30, 2018 at 11:01:48PM +0200, Marek Marczykowski-Górecki wrote:
> Tx response ID is fetched from shared page, so make sure it is sane
> before using it as an array index.
> 
> CC: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/net/xen-netfront.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
> index 934b8a4..55c9b25 100644
> --- a/drivers/net/xen-netfront.c
> +++ b/drivers/net/xen-netfront.c
> @@ -394,6 +394,7 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
>  				continue;
>  
>  			id  = txrsp.id;
> +			BUG_ON(id >= NET_TX_RING_SIZE);

It is better to use ARRAY_SIZE here.

Wei.