diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f380346..0093bc3 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2225,6 +2225,7 @@
 	if (mem_cgroup_disabled())
 		return;
 
+	VM_BUG_ON(!rcu_read_lock_held());
 	memcg = pc->mem_cgroup;
 	if (unlikely(!memcg || !PageCgroupUsed(pc)))
 		return;