diff --git a/kernel/ethosu_device.c b/kernel/ethosu_device.c
index 231c6d3..b63d068 100644
--- a/kernel/ethosu_device.c
+++ b/kernel/ethosu_device.c
@@ -242,7 +242,7 @@
 	struct ethosu_device *edev = dev_get_drvdata(&rpdev->dev);
 	struct device *dev = &edev->dev;
 	void __user *udata = (void __user *)arg;
-	int ret = -EINVAL;
+	int ret;
 
 	ret = device_lock_interruptible(dev);
 	if (ret)
@@ -278,8 +278,10 @@
 	case ETHOSU_IOCTL_BUFFER_CREATE: {
 		struct ethosu_uapi_buffer_create uapi;
 
-		if (copy_from_user(&uapi, udata, sizeof(uapi)))
+		if (copy_from_user(&uapi, udata, sizeof(uapi))) {
+			ret = -EFAULT;
 			break;
+		}
 
 		dev_info(dev,
 			 "Device ioctl: Buffer create. capacity=%u",
@@ -291,8 +293,10 @@
 	case ETHOSU_IOCTL_NETWORK_CREATE: {
 		struct ethosu_uapi_network_create uapi;
 
-		if (copy_from_user(&uapi, udata, sizeof(uapi)))
+		if (copy_from_user(&uapi, udata, sizeof(uapi))) {
+			ret = -EFAULT;
 			break;
+		}
 
 		dev_info(dev,
 			 "Device ioctl: Network create. type=%u, fd/index=%u",
@@ -304,6 +308,7 @@
 	default: {
 		dev_err(dev, "Invalid ioctl. cmd=%u, arg=%lu",
 			cmd, arg);
+		ret = -ENOIOCTLCMD;
 		break;
 	}
 	}