From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next 1/2] ipv6: remove unnecessary codes in
 tcp_ipv6.c
Date: Mon, 02 Jul 2012 10:54:41 +0200
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On Mon, 2012-07-02 at 10:13 +0200, Eric Dumazet wrote:

> Note that the old one is the np->opt of the listener, not the child.
> 
> I dont understand how np->opt could change under us, since we have
> the listener socket locked.
> 
> If np->opt can change under us, we are doomed and need to add refcounts.

Hmm, it seems net/ipv6/udp.c uses np->opt outside of the
lock_sock()/release_sock(sk) boundary.