Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/qrtr/tun.c b/net/qrtr/tun.c
index ccff1e5..e35869e 100644
--- a/net/qrtr/tun.c
+++ b/net/qrtr/tun.c
@@ -84,11 +84,14 @@
 	if (!kbuf)
 		return -ENOMEM;
 
-	if (!copy_from_iter_full(kbuf, len, from))
+	if (!copy_from_iter_full(kbuf, len, from)) {
+		kfree(kbuf);
 		return -EFAULT;
+	}
 
 	ret = qrtr_endpoint_post(&tun->ep, kbuf, len);
 
+	kfree(kbuf);
 	return ret < 0 ? ret : len;
 }