Fix crash when FormatMessageA sets lpBuffer to nullptr

The std::string constructor would try to perform a strlen() call on the invalid pointer
pkitszel · Mar 14, 2024 · df4c6a4 · df4c6a4
1 parent ab510c7
commit df4c6a4
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/src/util.cc b/src/util.cc
@@ -540,6 +540,13 @@ string GetLastErrorString() {
         (char*)&msg_buf,
         0,
         NULL);
+
+  if (msg_buf == nullptr) {
+    char fallback_msg[128] = {0};
+    snprintf(fallback_msg, sizeof(fallback_msg), "GetLastError() = %d", err);
+    return fallback_msg;
+  }
+
   string msg = msg_buf;
   LocalFree(msg_buf);
   return msg;