tree fa9d81be8ec27c49e3424fc4b2e30f41c2add9a5
parent aa32362f011c6e863132b16c1761487166a4bad2
author Zefan Li <lizefan@huawei.com> 1411032526 +0800
committer Tejun Heo <tj@kernel.org> 1411057972 -0400

cgroup: fix unbalanced locking

cgroup_pidlist_start() holds cgrp->pidlist_mutex and then calls
pidlist_array_load(), and cgroup_pidlist_stop() releases the mutex.

It is wrong that we release the mutex in the failure path in
pidlist_array_load(), because cgroup_pidlist_stop() will be called
no matter if cgroup_pidlist_start() returns errno or not.

Fixes: 4bac00d16a8760eae7205e41d2c246477d42a210
Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>