Eric Dumazet c5df581389 inet: make sure to grab rcu_read_lock before using ireq->ireq_opt
[ Upstream commit 2ab2ddd301a22ca3c5f0b743593e4ad2953dfa53 ]

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-18 09:16:21 +02:00
..
2016-04-27 22:48:25 -04:00
2018-05-16 10:10:24 +02:00
2015-11-01 17:01:16 -05:00
2018-05-19 10:20:23 +02:00