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Date:   Tue, 1 May 2018 11:05:16 +0100
From:   Wei Liu <wei.liu2@citrix.com>
To:     Marek =?iso-8859-1?Q?Marczykowski-G=F3recki?= 
        <marmarek@invisiblethingslab.com>
CC:     <xen-devel@lists.xenproject.org>, Juergen Gross <jgross@suse.com>,
        "open list:NETWORKING DRIVERS" <netdev@vger.kernel.org>,
        <stable@vger.kernel.org>, open list <linux-kernel@vger.kernel.org>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Wei Liu <wei.liu2@citrix.com>
Subject: Re: [Xen-devel] [PATCH 4/6] xen-netfront: add range check for Tx
 response id
Message-ID: <20180501100516.vjhop37we2rcrvyo@citrix.com>
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On Mon, Apr 30, 2018 at 11:01:48PM +0200, Marek Marczykowski-G?recki wrote:
> Tx response ID is fetched from shared page, so make sure it is sane
> before using it as an array index.
> 
> CC: stable@vger.kernel.org
> Signed-off-by: Marek Marczykowski-G?recki <marmarek@invisiblethingslab.com>
> ---
>  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.