From 01e089fd07f766aec13705b7a1c3d2805f1f9d5e Mon Sep 17 00:00:00 2001
From: Ben Meadors <benmmeadors@gmail.com>
Date: Wed, 24 Jul 2024 08:23:04 -0500
Subject: [PATCH] Ignore invalid service envelopes (#4326)

---
 src/mqtt/MQTT.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/mqtt/MQTT.cpp b/src/mqtt/MQTT.cpp
index 5f7d6d9027..a7085dffe3 100644
--- a/src/mqtt/MQTT.cpp
+++ b/src/mqtt/MQTT.cpp
@@ -135,6 +135,10 @@ void MQTT::onReceive(char *topic, byte *payload, size_t length)
             LOG_ERROR("Invalid MQTT service envelope, topic %s, len %u!\n", topic, length);
             return;
         } else {
+            if (e.channel_id == NULL || e.gateway_id == NULL) {
+                LOG_ERROR("Invalid MQTT service envelope, topic %s, len %u!\n", topic, length);
+                return;
+            }
             meshtastic_Channel ch = channels.getByName(e.channel_id);
             if (strcmp(e.gateway_id, owner.id) == 0) {
                 // Generate an implicit ACK towards ourselves (handled and processed only locally!) for this message.