From 63c2834d7bcb44706ec1ba1cb83d170465350b84 Mon Sep 17 00:00:00 2001
From: Roland Dobai <roland@espressif.com>
Date: Mon, 9 Sep 2019 15:02:38 +0200
Subject: [PATCH] VFS: Fix memory access after free() in UART select()

Closes https://github.com/espressif/esp-idf/issues/4030
---
 components/vfs/vfs_uart.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/components/vfs/vfs_uart.c b/components/vfs/vfs_uart.c
index 7a1d11352..c413cbfb0 100644
--- a/components/vfs/vfs_uart.c
+++ b/components/vfs/vfs_uart.c
@@ -474,10 +474,6 @@ static esp_err_t uart_end_select(void *end_select_args)
 {
     uart_select_args_t *args = end_select_args;
 
-    if (args) {
-        free(args);
-    }
-
     portENTER_CRITICAL(uart_get_selectlock());
     esp_err_t ret = unregister_select(args);
     for (int i = 0; i < UART_NUM; ++i) {
@@ -485,6 +481,10 @@ static esp_err_t uart_end_select(void *end_select_args)
     }
     portEXIT_CRITICAL(uart_get_selectlock());
 
+    if (args) {
+        free(args);
+    }
+
     return ret;
 }