diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 4683fe728c9b4baef4d9f703ab1e8edf11ab6374..7f384f4013b2c75dcbe48dcf7c848862d83ece71 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1438,10 +1438,9 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
 	struct mm_struct *mm;
 	struct cpuset *cs = cgroup_cs(cont);
 	struct cpuset *oldcs = cgroup_cs(oldcont);
-	NODEMASK_ALLOC(nodemask_t, from, GFP_KERNEL);
 	NODEMASK_ALLOC(nodemask_t, to, GFP_KERNEL);
 
-	if (from == NULL || to == NULL)
+	if (to == NULL)
 		goto alloc_fail;
 
 	if (cs == &top_cpuset) {
@@ -1463,18 +1462,16 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
 	}
 
 	/* change mm; only needs to be done once even if threadgroup */
-	*from = oldcs->mems_allowed;
 	*to = cs->mems_allowed;
 	mm = get_task_mm(tsk);
 	if (mm) {
 		mpol_rebind_mm(mm, to);
 		if (is_memory_migrate(cs))
-			cpuset_migrate_mm(mm, from, to);
+			cpuset_migrate_mm(mm, &oldcs->mems_allowed, to);
 		mmput(mm);
 	}
 
 alloc_fail:
-	NODEMASK_FREE(from);
 	NODEMASK_FREE(to);
 }