Clamp open file name size.

chrome/browser/views/shell_dialogs.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/shell_dialogs.h"
 
 #include <windows.h>
 #include <Commdlg.h>
 #include <shlobj.h>
 
@@ skipping 322 matching lines @@
 bool SelectFileDialogImpl::RunOpenFileDialog(const std::wstring& title,
                                              HWND owner,
                                              std::wstring* path) {
   OPENFILENAME ofn;
   // We must do this otherwise the ofn's FlagsEx may be initialized to random
   // junk in release builds which can cause the Places Bar not to show up!
   ZeroMemory(&ofn, sizeof(ofn));
   ofn.lStructSize = sizeof(ofn);
   ofn.hwndOwner = owner;
 
+  // This will clamp the number of characters copied from the supplied path
+  // to the value of MAX_PATH.
+  size_t name_size = std::min(path->length() + 1,
+                              static_cast<size_t>(MAX_PATH));
   wchar_t filename[MAX_PATH];
-  memcpy(filename, path->c_str(), (path->length()+1) * sizeof(wchar_t));
+  memcpy(filename, path->c_str(), name_size * sizeof(wchar_t));
+  filename[MAX_PATH - 1] = '\0';
 
   ofn.lpstrFile = filename;
   ofn.nMaxFile = MAX_PATH;
   ofn.Flags = OFN_FILEMUSTEXIST;
 
   // TODO(beng): (http://b/issue?id=1126563) edit the filter options in the
   //             dropdown list.
   bool success = !!GetOpenFileName(&ofn);
   DisableOwner(owner);
   if (success)
@@ skipping 163 matching lines @@
   if (listener_)
     listener_->FontSelectionCanceled(params);
   EndRun(run_state);
 }
 
 // static
 SelectFontDialog* SelectFontDialog::Create(Listener* listener) {
   return new SelectFontDialogImpl(listener);
 }