Fixed potential buffer overrun in Win32 OpenGL error handling

This fixes issue #1245.
SFML · Jan 19, 2019 · e12d28d · e12d28d
1 parent b516a3a
commit e12d28d
Showing 1 changed file with 10 additions and 6 deletions.
diff --git a/src/SFML/Window/Win32/WglContext.cpp b/src/SFML/Window/Win32/WglContext.cpp
@@ -66,13 +66,17 @@ void ensureExtensionsInit(HDC deviceContext)
 ////////////////////////////////////////////////////////////
 String getErrorString(DWORD errorCode)
 {
-    std::basic_ostringstream<TCHAR, std::char_traits<TCHAR> > ss;
-    TCHAR errBuff[256];
-    FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, errorCode, 0, errBuff, sizeof(errBuff), NULL);
-    ss << errBuff;
-    String errMsg(ss.str());
+    PTCHAR buffer;
+    if (FormatMessage(FORMAT_MESSAGE_MAX_WIDTH_MASK | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorCode, 0, reinterpret_cast<LPTSTR>(&buffer), 256, NULL) != 0)
+    {
+        String errMsg(buffer);
+        LocalFree(buffer);
+        return errMsg;
+    }
 
-    return errMsg;
+    std::ostringstream ss;
+    ss << "Error " << errorCode;
+    return String(ss.str());
 }