diff --git a/net/ipv4/fou_core.c b/net/ipv4/fou_core.c
index 3970b6b7ace53..7832d20454329 100644
--- a/net/ipv4/fou_core.c
+++ b/net/ipv4/fou_core.c
@@ -215,6 +215,9 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
 		return gue_control_message(skb, guehdr);
 
 	proto_ctype = guehdr->proto_ctype;
+	if (!proto_ctype)
+		goto drop;
+
 	__skb_pull(skb, sizeof(struct udphdr) + hdrlen);
 	skb_reset_transport_header(skb);