From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Lameter <cl@linux-foundation.org>
Subject: Re: [bug, netconsole, SLUB] BUG skbuff_head_cache: Poison overwritten
Date: Mon, 21 Jul 2008 11:22:27 -0500
Message-ID: <4884B7C3.9040801@linux-foundation.org>
References: <20080717214222.GA29449@elte.hu> <Pine.LNX.4.64.0807181149460.3852@sbz-30.cs.Helsinki.FI> <20080718091146.GQ6875@elte.hu> <20080721094110.GA16029@elte.hu> <84144f020807210252k68d5cf65i8c7ae3c11cecc046@mail.gmail.com> <20080721100627.GA5953@2ka.mipt.ru>
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Cc: Pekka Enberg <penberg@cs.helsinki.fi>, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	Vegard Nossum <vegard.nossum@gmail.com>,
	"Rafael J. Wysocki" <rjw@sisk.pl>, davem@davemloft.net
To: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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Evgeniy Polyakov wrote:
> Not that obvious...
> skb->next is cleared in lots of places, in xmit network helper
> for example, but since rest of the packet was not modified, it
> means given skb was not freed, so it will not help.
>
>   

The skb was definitely freed. 6b is written over an object when it is 
freed. Something else retained a pointer to the skb and was confident 
that the skb still exists.