From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] inet: make sure to grab rcu_read_lock before using
 ireq->ireq_opt
Date: Tue, 02 Oct 2018 15:52:36 -0700 (PDT)
Message-ID: <20181002.155236.1859184270596107590.davem@davemloft.net>
References: <20181002193505.48167-1-edumazet@google.com>
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From: Eric Dumazet <edumazet@google.com>
Date: Tue,  2 Oct 2018 12:35:05 -0700

> Timer handlers do not imply rcu_read_lock(), so my recent fix
> triggered a LOCKDEP warning when SYNACK is retransmit.
> 
> Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt
> usages instead of guessing what is done by callers, since it is
> not worth the pain.
> 
> Get rid of ireq_opt_deref() helper since it hides the logic
> without real benefit, since it is now a standard rcu_dereference().
> 
> Fixes: 1ad98e9d1bdf ("tcp/dccp: fix lockdep issue when SYN is backlogged")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: Willem de Bruijn <willemb@google.com>

Applied, thanks Eric.