From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: kernel BUG at kernel/timer.c:748!
Date: Mon, 24 Sep 2012 18:34:05 +0200
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Cc: Yuchung Cheng <ycheng@google.com>, Julian Anastasov <ja@ssi.bg>,
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To: Dave Jones <davej@redhat.com>
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On Mon, 2012-09-24 at 11:39 -0400, Dave Jones wrote:
> On Wed, Sep 19, 2012 at 10:02:23PM -0400, Dave Jones wrote:
>  > On Thu, Sep 20, 2012 at 12:01:22AM +0200, Eric Dumazet wrote:
>  > 
>  >  > I spent some time trying to track this bug, but found nothing so far.
>  >  > 
>  >  > The timer->function are never cleared by TCP stack at tear down, and
>  >  > should be set before fd is installed and can be caught by other threads.
>  >  > 
>  >  > Most likely its a refcounting issue...
>  >  > 
>  >  > Following debugging patch might trigger a bug sooner ?
>  > 
>  > 4 hours so far, nothing.. I'll leave it run overnight, but it doesn't seem to have
>  > made much difference if any.
> 
> One of my over-weekend runs hit this again, but it didn't trigger the WARN that
> your patch added :-/
> 
> 	Dave
> 

OK, I believe I found the reason. I Will post a patch.

open a raw socket AF_INET, TCP_PROTO
+ connect() ->sk_state set to TCP_ESTABLISHED
+ setsockopt( SO_KEEPALIVE, &on)  -> crash


Thanks