From 4bdd401e8b7384a685606f2254e634805580a2aa Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 27 Feb 2014 18:19:36 +0800 Subject: [PATCH] cpuset: fix a race condition in __cpuset_node_allowed_softwall() commit 99afb0fd5f05aac467ffa85c36778fec4396209b upstream. It's not safe to access task's cpuset after releasing task_lock(). Holding callback_mutex won't help. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- kernel/cpuset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index d313870..d9dd521 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2422,9 +2422,9 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask) task_lock(current); cs = nearest_hardwall_ancestor(task_cs(current)); + allowed = node_isset(node, cs->mems_allowed); task_unlock(current); - allowed = node_isset(node, cs->mems_allowed); mutex_unlock(&callback_mutex); return allowed; } -- 2.7.4