From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] net: check the length of the data before dereferencing
 it
Date: Mon, 02 Apr 2012 05:53:17 +0200
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Cc: David Miller <davem@davemloft.net>, kaber@trash.net,
	pablo@netfilter.org, netfilter-devel@vger.kernel.org,
	netdev@vger.kernel.org
To: Changli Gao <xiaosuo@gmail.com>
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On Mon, 2012-04-02 at 11:45 +0800, Changli Gao wrote:

> Thinking about a malformed tcp segment, which has no data but silly
> options, and whose last byte is neither TCPOPT_EOL or TCPOPT_NOP, we
> will try to dereference one byte over the boundary when parsing the
> options. I know we have skb_shared_info at the end and it won't cause
> any crash, but should we rely on this fact?
> 

No we cant rely on this, kmemcheck might barf on us.

Your patch (and the netfilter one) is fine.