mqtt: free 'sendleftovers' in disconnect

Fix a memory-leak

Bug: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=43646
Closes #8415

diff --git a/lib/mqtt.c b/lib/mqtt.c
index e0fa0aa8fb17f3193d797d0a41cf8ab22f692bf6..e79bd3b48215825cd85133cd764bb2bd69739d31 100644 (file)
--- a/lib/mqtt.c
+++ b/lib/mqtt.c
@@ -346,7 +346,9 @@ end:
 static CURLcode mqtt_disconnect(struct Curl_easy *data)
 {
   CURLcode result = CURLE_OK;
+  struct MQTT *mq = data->req.p.mqtt;
   result = mqtt_send(data, (char *)"\xe0\x00", 2);
+  Curl_safefree(mq->sendleftovers);
   return result;
 }