From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] ipv6: tcp: fix race in IPV6_2292PKTOPTIONS
Date: Mon, 26 Jan 2015 00:44:28 -0800 (PST)
Message-ID: <20150126.004428.66350757054974030.davem@davemloft.net>
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 21 Jan 2015 03:45:42 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> IPv6 TCP sockets store in np->pktoptions skbs, and use skb_set_owner_r()
> to charge the skb to socket.
> 
> It means that destructor must be called while socket is locked.
> 
> Therefore, we cannot use skb_get() or atomic_inc(&skb->users)
> to protect ourselves : kfree_skb() might race with other users
> manipulating sk->sk_forward_alloc
> 
> Fix this race by holding socket lock for the duration of
> ip6_datagram_recv_ctl()
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
>  Since this bug is very old, feel free to apply on net-next ;)

Applied to net-next, thanks Eric.