diff --git a/kernel/fork.c b/kernel/fork.c
index 9276927..8e7e135 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -485,6 +485,20 @@
 #endif
 }
 
+int mm_init_cpumask(struct mm_struct *mm, struct mm_struct *oldmm)
+{
+#ifdef CONFIG_CPUMASK_OFFSTACK
+	if (!alloc_cpumask_var(&mm->cpu_vm_mask_var, GFP_KERNEL))
+		return -ENOMEM;
+
+	if (oldmm)
+		cpumask_copy(mm_cpumask(mm), mm_cpumask(oldmm));
+	else
+		memset(mm_cpumask(mm), 0, cpumask_size());
+#endif
+	return 0;
+}
+
 static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
 	atomic_set(&mm->mm_users, 1);
@@ -521,10 +535,20 @@
 	struct mm_struct * mm;
 
 	mm = allocate_mm();
-	if (mm) {
-		memset(mm, 0, sizeof(*mm));
-		mm = mm_init(mm, current);
+	if (!mm)
+		return NULL;
+
+	memset(mm, 0, sizeof(*mm));
+	mm = mm_init(mm, current);
+	if (!mm)
+		return NULL;
+
+	if (mm_init_cpumask(mm, NULL)) {
+		mm_free_pgd(mm);
+		free_mm(mm);
+		return NULL;
 	}
+
 	return mm;
 }
 
@@ -536,6 +560,7 @@
 void __mmdrop(struct mm_struct *mm)
 {
 	BUG_ON(mm == &init_mm);
+	free_cpumask_var(mm->cpu_vm_mask_var);
 	mm_free_pgd(mm);
 	destroy_context(mm);
 	mmu_notifier_mm_destroy(mm);
@@ -690,6 +715,9 @@
 	if (!mm_init(mm, tsk))
 		goto fail_nomem;
 
+	if (mm_init_cpumask(mm, oldmm))
+		goto fail_nocpumask;
+
 	if (init_new_context(tsk, mm))
 		goto fail_nocontext;
 
@@ -716,6 +744,9 @@
 	return NULL;
 
 fail_nocontext:
+	free_cpumask_var(mm->cpu_vm_mask_var);
+
+fail_nocpumask:
 	/*
 	 * If init_new_context() failed, we cannot use mmput() to free the mm
 	 * because it calls destroy_context()