diff --git a/kernel/sched.c b/kernel/sched.c
index 9ab3cd7858d3..6eaef3df2d19 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4902,7 +4902,9 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
 	int ret;
 	cpumask_var_t mask;
 
-	if (len < cpumask_size())
+	if (len < nr_cpu_ids)
+		return -EINVAL;
+	if (len & (sizeof(unsigned long)-1))
 		return -EINVAL;
 
 	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
@@ -4910,10 +4912,12 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
 
 	ret = sched_getaffinity(pid, mask);
 	if (ret == 0) {
-		if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
+		int retlen = min(len, cpumask_size());
+
+		if (copy_to_user(user_mask_ptr, mask, retlen))
 			ret = -EFAULT;
 		else
-			ret = cpumask_size();
+			ret = retlen;
 	}
 	free_cpumask_var(mask);