diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c1e64d60ed02..5a3873e9d657 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5480,6 +5480,10 @@ enum mem_cgroup_protection mem_cgroup_protected(struct mem_cgroup *root,
 	elow = memcg->memory.low;
 
 	parent = parent_mem_cgroup(memcg);
+	/* No parent means a non-hierarchical mode on v1 memcg */
+	if (!parent)
+		return MEMCG_PROT_NONE;
+
 	if (parent == root)
 		goto exit;