From 99afb0fd5f05aac467ffa85c36778fec4396209b 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() It's not safe to access task's cpuset after releasing task_lock(). Holding callback_mutex won't help. Cc: Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- kernel/cpuset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index dba9e4aef69a..e6b1b66afe52 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2482,9 +2482,9 @@ 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; } -- 2.30.2