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From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: netdev@vger.kernel.org
Subject: Re: [BUG] eth_type_trans() can access stale data
Date: Wed, 15 Jan 2014 15:48:05 -0800 (PST)	[thread overview]
Message-ID: <20140115.154805.1403628531019301276.davem@davemloft.net> (raw)
In-Reply-To: <1389743541.31367.279.camel@edumazet-glaptop2.roam.corp.google.com>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 14 Jan 2014 15:52:21 -0800

> @@ -194,7 +194,8 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
>  	 *      layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
>  	 *      won't work for fault tolerant netware but does for the rest.
>  	 */
> -	if (unlikely(skb->len >= 2 && *(unsigned short *)(skb->data) == 0xFFFF))
> +	if (unlikely(skb_headlen(skb) >= 2 &&
> +		     *(unsigned short *)(skb->data) == 0xFFFF))
>  		return htons(ETH_P_802_3);

I think using skb_header_pointer() will essentially have the same cost,
why not use it instead?

Thanks.

  parent reply	other threads:[~2014-01-15 23:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-14 23:52 [BUG] eth_type_trans() can access stale data Eric Dumazet
2014-01-15  0:21 ` Ben Hutchings
2014-01-16 23:03   ` [PATCH net-next] net: eth_type_trans() should use skb_header_pointer() Eric Dumazet
2014-01-16 23:30     ` David Miller
2014-01-15 23:48 ` David Miller [this message]
2014-01-16 20:15   ` [BUG] eth_type_trans() can access stale data Eric Dumazet

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