From 87a41fabfa9431b136dd94e01180aab98cf2dbcf Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Tue, 10 Dec 2019 15:28:21 +0100
Subject: [PATCH] esp-tls: check return value of fcntl

---
 components/esp-tls/esp_tls.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/components/esp-tls/esp_tls.c b/components/esp-tls/esp_tls.c
index af2be302db..ba9e758126 100644
--- a/components/esp-tls/esp_tls.c
+++ b/components/esp-tls/esp_tls.c
@@ -189,7 +189,11 @@ static esp_err_t esp_tcp_connect(const char *host, int hostlen, int port, int *s
         }
         if (cfg->non_block) {
             int flags = fcntl(fd, F_GETFL, 0);
-            fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+            ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+            if (ret < 0) {
+                ESP_LOGE(TAG, "Failed to configure the socket as non-blocking (errno %d)", errno);
+                goto err_freesocket;
+            }
         }
     }