From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] tproxy: nf_tproxy_assign_sock() can handle tw sockets
Date: Tue, 13 Jul 2010 17:49:53 +0200
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Cc: Avi Kivity <avi@redhat.com>, David Miller <davem@davemloft.net>,
	Patrick McHardy <kaber@trash.net>,
	linux-kernel@vger.kernel.org, netdev <netdev@vger.kernel.org>
To: Felipe W Damasio <felipewd@gmail.com>
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Le mardi 13 juillet 2010 =C3=A0 11:49 -0300, Felipe W Damasio a =C3=A9c=
rit :
> Hi Mr. Dumazet,
>=20
> 2010/7/13 Eric Dumazet <eric.dumazet@gmail.com>:
> > I currently have no fresh ideas. If you want this problem to be sol=
ved,
> > its important to setup in your lab a workload to trigger again and =
again
> > the bug, in order to provide us more crash information.
>=20
>  Right. I've been running non-stop since the first bug happened, but
> so far the problem hasn't surfaced again :-(
>=20
>  I've been using the kernel with the patch that you provided me
> (nf_tproxy.c). Is there a chance that patch fixed the problem?

This is a real bug, but I dont think it can fix your problem.

Looking again at your crash, we see RCX=3D0x720, decimal 1824

As its skb->len, we are freeing an skb that was collapsed or something
like that, since 1824 > 1460 (the normal MSS on ethernet)

GRO is off on your machine.

But coincidently 0x0720 is also a blank char for VGA screen...
(0x20 : ASCII space, 0x07 : default attribute)

So maybe you hit a corruption outside of network stack.