diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index d832062869f6..ba4a38b9c22f 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -95,7 +95,7 @@ static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
  */
 static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
 {
-	struct autofs_dev_ioctl tmp, *ads;
+	struct autofs_dev_ioctl tmp;
 
 	if (copy_from_user(&tmp, in, sizeof(tmp)))
 		return ERR_PTR(-EFAULT);
@@ -103,16 +103,7 @@ static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *i
 	if (tmp.size < sizeof(tmp))
 		return ERR_PTR(-EINVAL);
 
-	ads = kmalloc(tmp.size, GFP_KERNEL);
-	if (!ads)
-		return ERR_PTR(-ENOMEM);
-
-	if (copy_from_user(ads, in, tmp.size)) {
-		kfree(ads);
-		return ERR_PTR(-EFAULT);
-	}
-
-	return ads;
+	return memdup_user(in, tmp.size);
 }
 
 static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)