diff --git a/mm/vmscan.c b/mm/vmscan.c
index e83d2a74e942..bf3eedf0209c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3323,13 +3323,16 @@ void lru_gen_migrate_mm(struct mm_struct *mm)
 	if (mem_cgroup_disabled())
 		return;
 
+	/* migration can happen before addition */
+	if (!mm->lru_gen.memcg)
+		return;
+
 	rcu_read_lock();
 	memcg = mem_cgroup_from_task(task);
 	rcu_read_unlock();
 	if (memcg == mm->lru_gen.memcg)
 		return;
 
-	VM_WARN_ON_ONCE(!mm->lru_gen.memcg);
 	VM_WARN_ON_ONCE(list_empty(&mm->lru_gen.list));
 
 	lru_gen_del_mm(mm);