tree 054fec600d1a1b77d1ea73289423dd07db1b18a3
parent 2a4eebf0c485d8e90bdd2e33e75c4b3b1e1673ac
author Eric Dumazet <edumazet@google.com> 1439505891 -0700
committer David S. Miller <davem@davemloft.net> 1439531182 -0700

inet: fix potential deadlock in reqsk_queue_unlink()

When replacing del_timer() with del_timer_sync(), I introduced
a deadlock condition :

reqsk_queue_unlink() is called from inet_csk_reqsk_queue_drop()

inet_csk_reqsk_queue_drop() can be called from many contexts,
one being the timer handler itself (reqsk_timer_handler()).

In this case, del_timer_sync() loops forever.

Simple fix is to test if timer is pending.

Fixes: 2235f2ac75fd ("inet: fix races with reqsk timers")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>