From 4401c71d0caf324b075cd0aa5c6f77e99d5a6ac7 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sat, 4 Mar 2017 10:27:19 +0100 Subject: [PATCH] futex: Add missing error handling to FUTEX_REQUEUE_PI commit 9bbb25afeb182502ca4f2c4f3f88af0681b34cae upstream. Thomas spotted that fixup_pi_state_owner() can return errors and we fail to unlock the rt_mutex in that case. Reported-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Darren Hart Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: dvhart@infradead.org Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170304093558.867401760@infradead.org Signed-off-by: Thomas Gleixner Signed-off-by: Willy Tarreau --- kernel/futex.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/futex.c b/kernel/futex.c index 01a72fc87265..3f7dd29f4d4d 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2493,6 +2493,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, if (q.pi_state && (q.pi_state->owner != current)) { spin_lock(q.lock_ptr); ret = fixup_pi_state_owner(uaddr2, &q, current); + if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current) + rt_mutex_unlock(&q.pi_state->pi_mutex); /* * Drop the reference to the pi state which * the requeue_pi() code acquired for us. -- 2.20.1