ipvs: Fix possible deadlock in estimator code
There is a slight chance for a deadlock in the estimator code. We can't call del_timer_sync() while holding our lock, as the timer might be active and spinning for the lock on another cpu. Work around this issue by using try_to_del_timer_sync() and releasing the lock. We could actually delete the timer outside of our lock, as the add and kill functions are only every called from userspace via [gs]etsockopt() and are serialized by a mutex, but better make this explicit. Signed-off-by: Sven Wegener <sven.wegener@stealer.net> Cc: stable <stable@kernel.org> Acked-by: Simon Horman <horms@verge.net.au>
This commit is contained in:
parent
bc0fde2fad
commit
8ab19ea36c
|
@ -170,8 +170,11 @@ void ip_vs_kill_estimator(struct ip_vs_stats *stats)
|
|||
kfree(est);
|
||||
killed++;
|
||||
}
|
||||
if (killed && est_list == NULL)
|
||||
del_timer_sync(&est_timer);
|
||||
while (killed && !est_list && try_to_del_timer_sync(&est_timer) < 0) {
|
||||
write_unlock_bh(&est_lock);
|
||||
cpu_relax();
|
||||
write_lock_bh(&est_lock);
|
||||
}
|
||||
write_unlock_bh(&est_lock);
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in New Issue