netdev - Re: [PATCH nf-next v4 1/2] netfilter: Fix potential null pointer dereference

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Message-ID: <20160930174152.GC1176@salvia>
Date:   Fri, 30 Sep 2016 19:41:52 +0200
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     Aaron Conole <aconole@...heb.org>
Cc:     netfilter-devel@...r.kernel.org, netdev@...r.kernel.org,
        Florian Westphal <fw@...len.de>
Subject: Re: [PATCH nf-next v4 1/2] netfilter: Fix potential null pointer
 dereference

On Wed, Sep 28, 2016 at 11:35:14AM -0400, Aaron Conole wrote:
> It's possible for nf_hook_entry_head to return NULL.  If two
> nf_unregister_net_hook calls happen simultaneously with a single hook
> entry in the list, both will enter the nf_hook_mutex critical section.
> The first will successfully delete the head, but the second will see
> this NULL pointer and attempt to dereference.
> 
> This fix ensures that no null pointer dereference could occur when such
> a condition happens.

Applied, thanks Aaron.