diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index c89ae52764b8..157fc23ce4e1 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1290,6 +1290,11 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, uns
 		uh->source = inet->inet_sport;
 		uh->dest = inet->inet_dport;
 		udp_len = uhlen + session->hdr_len + data_len;
+		if (udp_len > U16_MAX) {
+			kfree_skb(skb);
+			ret = NET_XMIT_DROP;
+			goto out_unlock;
+		}
 		uh->len = htons(udp_len);
 
 		/* Calculate UDP checksum if configured to do so */