commit b328ffe8ed1318c3380f6b46cffee854b23f16fb
author Linux Build Service Account <lnxbuild@localhost> Fri Sep 26 05:26:27 2014 -0700
committer Gerrit - the friendly Code Review server <code-review@localhost> Fri Sep 26 05:26:26 2014 -0700
tree 222a1180b9a316be343d53caa9a5b95b0d19ad43
parent 83d17d0cb85df82903d43c4a219f3ebd31bef65b
parent 4ac97cf6dc2fb87017a51ae533b932f5a2013c9f

Merge "kernel: cgroup: protecting css_set object"

kernel/cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 63a0bdc..ee34e81 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3965,12 +3965,16 @@
 {
 	struct cg_cgroup_link *link;
 
+	read_lock(&css_set_lock);
 	list_for_each_entry(link, &cgrp->css_sets, cgrp_link_list) {
 		struct css_set *cg = link->cg;
-		if (atomic_read(&cg->refcount) > 0)
+		if (cg && (atomic_read(&cg->refcount) > 0)) {
+			read_unlock(&css_set_lock);
 			return 0;
+		}
 	}
 
+	read_unlock(&css_set_lock);
 	return 1;
 }