From 1b6f827b2c1c782e4a8061a7c476775309865ee5 Mon Sep 17 00:00:00 2001
From: Wilhelm <wilhelm.wm.meier@googlemail.com>
Date: Mon, 10 Jan 2022 00:28:47 +0100
Subject: [PATCH] fix: Potential out of bounds access of flightmode name on
 main screen (#1337)

* fixed incorrect use of non-terminated-fixed-string for ctor of std::string

* introduced helper

* removed commented lines
---
 radio/src/gui/colorlcd/view_main_decoration.cpp | 4 ++--
 radio/src/strhelpers.h                          | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/radio/src/gui/colorlcd/view_main_decoration.cpp b/radio/src/gui/colorlcd/view_main_decoration.cpp
index 0066efef0..a156eb015 100644
--- a/radio/src/gui/colorlcd/view_main_decoration.cpp
+++ b/radio/src/gui/colorlcd/view_main_decoration.cpp
@@ -328,8 +328,8 @@ void ViewMainDecoration::createFlightMode()
   };
 
   std::function<std::string()> getFM = []() -> std::string {
-    return g_model.flightModeData[mixerCurrentFlightMode].name;
-  };
+      return stringFromNtString(g_model.flightModeData[mixerCurrentFlightMode].name);
+};
 
   flightMode = new DynamicText(this, r, getFM, CENTERED | COLOR_THEME_SECONDARY1);
 }
diff --git a/radio/src/strhelpers.h b/radio/src/strhelpers.h
index 683de26d4..c7c08c86f 100644
--- a/radio/src/strhelpers.h
+++ b/radio/src/strhelpers.h
@@ -25,6 +25,8 @@
 #include "definitions.h"
 #include "opentx_types.h"
 
+#include <string>
+
 #define SHOW_TIME  0x1
 #define SHOW_TIMER 0x0
 #define SHOW_TIMER_UPPER_CASE   0x2
@@ -90,4 +92,8 @@ char *getTimerString(int32_t tme, TimerOptions timerOptions = {.options = 0});
 void splitTimer(char *s0, char *s1, char *s2, char *s3, int tme,
                 bool bLowercase = true);
 
+template<size_t N>
+constexpr std::string stringFromNtString(const char (&a)[N]) {
+    return std::string(a, strnlen(a, N));        
+}    
 #endif  // _STRHELPERS_H_