cpuset: fix a race condition in __cpuset_node_allowed_softwall()

It's not safe to access task's cpuset after releasing task_lock().
Holding callback_mutex won't help.

Cc: <stable@vger.kernel.org>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Li Zefan 2014-02-27 18:19:36 +08:00 committed by Tejun Heo
parent 4729583006
commit 99afb0fd5f

View File

@ -2482,9 +2482,9 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
task_lock(current); task_lock(current);
cs = nearest_hardwall_ancestor(task_cs(current)); cs = nearest_hardwall_ancestor(task_cs(current));
allowed = node_isset(node, cs->mems_allowed);
task_unlock(current); task_unlock(current);
allowed = node_isset(node, cs->mems_allowed);
mutex_unlock(&callback_mutex); mutex_unlock(&callback_mutex);
return allowed; return allowed;
} }