From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pablo Neira Ayuso <pablo@netfilter.org>
Subject: Re: [PATCH] netfilter: synproxy: fix BUG_ON triggered by corrupt TCP
 packets
Date: Mon, 30 Sep 2013 12:45:54 +0200
Message-ID: <20130930104554.GA5462@localhost>
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To: Patrick McHardy <kaber@trash.net>
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On Mon, Sep 30, 2013 at 08:51:46AM +0100, Patrick McHardy wrote:
> TCP packets hitting the SYN proxy through the SYNPROXY target are not
> validated by TCP conntrack. When th->doff is below 5, an underflow happens
> when calculating the options length, causing skb_header_pointer() to
> return NULL and triggering the BUG_ON().
> 
> Handle this case gracefully by checking for NULL instead of using BUG_ON().

Applied, thanks Patrick!