From 6a6fccc1918f14fd807a5b7c432f557c409debc1 Mon Sep 17 00:00:00 2001
From: David Cermak <cermak@espressif.com>
Date: Mon, 22 Oct 2018 16:45:42 +0200
Subject: [PATCH] mdns: fixed crashes on network change (not properly locked
 sending packets to queue from timer task), backport 3.1

---
 components/mdns/mdns.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/components/mdns/mdns.c b/components/mdns/mdns.c
index 43c3240f92..31fb592f29 100644
--- a/components/mdns/mdns.c
+++ b/components/mdns/mdns.c
@@ -3779,13 +3779,14 @@ static esp_err_t _mdns_send_search_action(mdns_action_type_t type, mdns_search_o
  */
 static void _mdns_scheduler_run()
 {
+    MDNS_SERVICE_LOCK();
     mdns_tx_packet_t * p = _mdns_server->tx_queue_head;
     mdns_action_t * action = NULL;
 
     if (!p) {
+        MDNS_SERVICE_UNLOCK();
         return;
     }
-    MDNS_SERVICE_LOCK();
     if ((int32_t)(p->send_at - (xTaskGetTickCount() * portTICK_PERIOD_MS)) < 0) {
         action = (mdns_action_t *)malloc(sizeof(mdns_action_t));
         if (action) {