From dca0b366acd13908260cd0082d49ba44196a2411 Mon Sep 17 00:00:00 2001
From: Jose Alamos <jose@alamos.cc>
Date: Mon, 1 Mar 2021 15:44:17 +0100
Subject: [PATCH] gnrc_lorawan: drop frame if port exceeds max app port

---
 sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c
index ff6e2b1b49..41ca6c7eba 100644
--- a/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c
+++ b/sys/net/gnrc/link_layer/lorawan/gnrc_lorawan_mcps.c
@@ -118,6 +118,11 @@ int gnrc_lorawan_parse_dl(gnrc_lorawan_t *mac, uint8_t *buf, size_t len,
             return -1;
         }
 
+        if (pkt->port > LORAMAC_PORT_MAX) {
+            DEBUG("gnrc_lorawan: packet with port > 223. Drop\n");
+            return -1;
+        }
+
         if (buf < p_mic) {
             pkt->enc_payload.iol_base = buf;
             pkt->enc_payload.iol_len = p_mic - buf;