From: Paul Moore <paul.moore@hp.com>
Organization: Hewlett-Packard
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Subject: Re: [TOMOYO #5 18/18] LSM expansion for TOMOYO Linux.
Date: Mon, 19 Nov 2007 10:39:41 -0500
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Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
       linux-security-module@vger.kernel.org, takedakn@nttdata.co.jp
References: <20071116173439.796600895@I-love.SAKURA.ne.jp> <200711190836.12940.paul.moore@hp.com> <200711192329.JGB18772.tLHOOSMVFFQOFJ@I-love.SAKURA.ne.jp>
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On Monday 19 November 2007 9:29:52 am Tetsuo Handa wrote:
> Paul Moore wrote:
> > If that is the case then the second call to
> > skb_peek() will return a different skb then the one you passed to
> > security_post_recv_datagram().
>
> Yes. The second call to skb_peek() might return a different skb than the
> one I passed to security_post_recv_datagram().

My apologies, I mistakenly read the following if statement in your patch:

 +???????if (skb == skb_peek(&sk->sk_receive_queue)) {
 +???????????????__skb_unlink(skb, &sk->sk_receive_queue);
 +???????????????atomic_dec(&skb->users);
 +???????}

I read the conditional as the following:

 +       if (skb = skb_peek(&sk->sk_receive_queue)) {

... which would have caused the problems I was describing.  I'm sorry for all 
of the confusion/frustration, you patient explanations are correct; I was 
wrong in this particular case.

-- 
paul moore
linux security @ hp
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