Re: [PATCH] netfilter: fix ->nfnl NULL oops

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Tue, Nov 08, 2011 at 10:50:05PM +0000, Alex Bligh wrote:
> --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.

That's news.

I personally NACKed that patch.

Can you confirm that, please?