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From: Chris Mason <clm@fb.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: <netdev@vger.kernel.org>
Subject: Re: crash in __kfree_skb on v3.18-rc5 with CONFIG_DEBUG_PAGEALLOC
Date: Fri, 21 Nov 2014 11:47:06 -0500	[thread overview]
Message-ID: <1416588426.24312.6@mail.thefacebook.com> (raw)
In-Reply-To: <1416587848.8629.108.camel@edumazet-glaptop2.roam.corp.google.com>



On Fri, Nov 21, 2014 at 11:37 AM, Eric Dumazet <eric.dumazet@gmail.com> 
wrote:
> On Fri, 2014-11-21 at 08:31 -0800, Eric Dumazet wrote:
> 
>>  Can you double check, or send whole __kfree_skb() disassembly ?
>> 
>>  I do not understand how skb->fclone could possibly trap _at_ this 
>> point.
> 
> Oh well, I think commit ce1a4ea3f1258 ("net: avoid one atomic 
> operation
> in skb_clone()") is the problem, I'll send a revert.

Once my current run is done, I can revert this and try a loop.  But I 
don't see how this commit causes a use-after-free on the skb itself?

-chris

  reply	other threads:[~2014-11-21 16:47 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-21 16:16 crash in __kfree_skb on v3.18-rc5 with CONFIG_DEBUG_PAGEALLOC Chris Mason
2014-11-21 16:31 ` Eric Dumazet
2014-11-21 16:37   ` Eric Dumazet
2014-11-21 16:47     ` Chris Mason [this message]
2014-11-21 16:56       ` Eric Dumazet
2014-11-21 17:18         ` Chris Mason
2014-11-21 16:41   ` Chris Mason
2014-11-21 16:57   ` Chris Mason
2014-11-21 17:04   ` [PATCH net] net: Revert "net: avoid one atomic operation in skb_clone()" Eric Dumazet
2014-11-21 18:05     ` Sabrina Dubroca
2014-11-21 19:29       ` Eric Dumazet
2014-11-21 19:39         ` Chris Mason
2014-11-21 19:47         ` [PATCH v2 " Eric Dumazet
2014-11-21 20:27           ` David Miller
2014-11-21 21:15           ` Chris Mason
2014-11-21 16:33 ` crash in __kfree_skb on v3.18-rc5 with CONFIG_DEBUG_PAGEALLOC Chris Mason

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