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From: Alex Bligh <alex@alex.org.uk>
To: Alexey Dobriyan <adobriyan@gmail.com>, pablo@netfilter.org
Cc: kaber@trash.net, netfilter-devel@vger.kernel.org,
	Alex Bligh <alex@alex.org.uk>
Subject: Re: [PATCH] netfilter: fix ->nfnl NULL oops
Date: Tue, 08 Nov 2011 22:50:05 +0000	[thread overview]
Message-ID: <32FF200DF1281ACA19CF3807@nimrod.local> (raw)
In-Reply-To: <20111108221634.GA13261@p183.telecom.by>

--On 9 November 2011 01:16:35 +0300 Alexey Dobriyan <adobriyan@gmail.com> 
wrote:

> Sorry for delay.
>
> I recall myself writing that net->nfnl NULL check is racy or
> something like that (but I can't find this email in archives).
>
> I've read the code once again, and I'm quite sure,
> NULL ->nfnl check is correct if RCU precautions are made.

Your patch looks better than mine in this respect (as far as I
can tell from code reading rather than testing)

> Regarding ->report check, I think it's bogus.

All I can tell is that net->nfnl == NULL is a condition that happens in 
practice. If that is read, race free, and treated as something that causes 
nfnetlink_has_listeners to return 0 irrespective of item_report, then the 
oops will not occur. So from my point of view it seems right.

Note that in the mean time I think my patch made -stable.

-- 
Alex Bligh

  reply	other threads:[~2011-11-08 22:56 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-08 22:16 [PATCH] netfilter: fix ->nfnl NULL oops Alexey Dobriyan
2011-11-08 22:50 ` Alex Bligh [this message]
2011-11-09 14:35   ` Pablo Neira Ayuso
2011-11-09 19:04     ` Alex Bligh
2011-11-09 14:34 ` Pablo Neira Ayuso
2011-11-09 19:06   ` Alex Bligh
2011-11-15  9:56   ` Pablo Neira Ayuso
2011-11-15 10:13     ` Alex Bligh
2011-11-15 14:09       ` Pablo Neira Ayuso
2011-11-21 23:39       ` Pablo Neira Ayuso
2011-11-21 23:42         ` Pablo Neira Ayuso
2011-11-21 23:50         ` Alex Bligh
2011-11-22 14:23           ` Pablo Neira Ayuso

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