cgroup: fix rcu_read_lock() leak in update_if_frozen()
authorTejun Heo <tj@kernel.org>
Tue, 13 May 2014 15:28:30 +0000 (11:28 -0400)
committerTejun Heo <tj@kernel.org>
Tue, 13 May 2014 15:28:30 +0000 (11:28 -0400)
While updating cgroup_freezer locking, 68fafb77d827 ("cgroup_freezer:
replace freezer->lock with freezer_mutex") introduced a bug in
update_if_frozen() where it returns with rcu_read_lock() held.  Fix it
by adding rcu_read_unlock() before returning.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
kernel/cgroup_freezer.c

index 12ead0b766eed5b1bb844fd5c24316f1473e386b..345628c78b5b3779460038ec6f036f9e8b7c1a32 100644 (file)
@@ -267,8 +267,10 @@ static void update_if_frozen(struct cgroup_subsys_state *css)
                struct freezer *child = css_freezer(pos);
 
                if ((child->state & CGROUP_FREEZER_ONLINE) &&
-                   !(child->state & CGROUP_FROZEN))
+                   !(child->state & CGROUP_FROZEN)) {
+                       rcu_read_unlock();
                        return;
+               }
        }
        rcu_read_unlock();