From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [Patch net] garp: fix a NULL pointer dereference bug
Date: Mon, 04 Mar 2013 06:56:15 -0800
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Cc: netdev@vger.kernel.org, bugs@syam.in,
	David Ward <david.ward@ll.mit.edu>,
	Stephen Hemminger <stephen@networkplumber.org>,
	"David S. Miller" <davem@davemloft.net>
To: Cong Wang <amwang@redhat.com>
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On Mon, 2013-03-04 at 17:55 +0800, Cong Wang wrote:
> On Sun, 2013-03-03 at 21:26 -0800, Eric Dumazet wrote:
> > 
> > Nope this patch doesnt solve the problem
> > 
> > Crash is in :
> > 
> > 49 8b 1c c6             mov    (%r14,%rax,8),%rbx 
> > 
> > Thats because r14 (port) is NULL
> > 
> > 
> > 
> 
> Hmm, but I can't see how it can be NULL, the only place of NULL'ing it
> is inside garp_release_port(), right after the piece of code that I
> patched.
> 
> Thanks!
> 

Maybe port is NULL from the beginning.

Try to inject memory allocations error in garp_init_port()