Windows sbox: Warmup locales before sandbox lockdown (and tests)

sandbox/win/src/target_services.cc

 // Copyright (c) 2012 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 "sandbox/win/src/target_services.h"
 
 #include <new>
 
 #include <process.h>
 
@@ skipping 41 matching lines @@
   if (sandbox::HandleCloserAgent::NeedsHandlesClosed()) {
     sandbox::HandleCloserAgent handle_closer;
     handle_closer.InitializeHandlesToClose(is_csrss_connected);
     if (!handle_closer.CloseHandles())
       return false;
   }
 
   return true;
 }
 
+// Warm up language subsystems before the sandbox is turned on.
+// Tested on Win8.1 x64:
+// This needs to happen after RevertToSelf() is called, because (at least) in
+// the case of GetUserDefaultLCID() it checks the TEB to see if the process is
+// impersonating (TEB!IsImpersonating). If it is, the cached locale information
+// is not used, nor is it set. Therefore, calls after RevertToSelf() will not
+// have warmed-up values to use.
+bool WarmupWindowsLocales() {
+  // NOTE(liamjm): When last checked (Win 8.1 x64) it wasn't necessary to
+  // warmup all of these functions, but let's not assume that.
+  ::GetUserDefaultLangID();
+  ::GetUserDefaultLCID();
+  wchar_t localeName[LOCALE_NAME_MAX_LENGTH] = { 0 };
+  return (0 != ::GetUserDefaultLocaleName(
+      localeName, LOCALE_NAME_MAX_LENGTH * sizeof(wchar_t)));
+}
 
 // Used as storage for g_target_services, because other allocation facilities
 // are not available early. We can't use a regular function static because on
 // VS2015, because the CRT tries to acquire a lock to guard initialization, but
 // this code runs before the CRT is initialized.
 char g_target_services_memory[sizeof(sandbox::TargetServicesBase)];
 sandbox::TargetServicesBase* g_target_services = nullptr;
 
 }  // namespace
 
@@ skipping 18 matching lines @@
     ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_INTEGRITY);
   process_state_.SetRevertedToSelf();
   // If the client code as called RegOpenKey, advapi32.dll has cached some
   // handles. The following code gets rid of them.
   if (!::RevertToSelf())
     ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_DROPTOKEN);
   if (!FlushCachedRegHandles())
     ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_FLUSHANDLES);
   if (ERROR_SUCCESS != ::RegDisablePredefinedCache())
     ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_CACHEDISABLE);
+  if (!WarmupWindowsLocales())
+      ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_WARMUP);
   bool is_csrss_connected = true;
   if (!CloseOpenHandles(&is_csrss_connected))
     ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_CLOSEHANDLES);
   process_state_.SetCsrssConnected(is_csrss_connected);
   // Enabling mitigations must happen last otherwise handle closing breaks
   if (g_shared_delayed_mitigations &&
       !ApplyProcessMitigationsToCurrentProcess(g_shared_delayed_mitigations))
     ::TerminateProcess(::GetCurrentProcess(), SBOX_FATAL_MITIGATION);
 }
 
@@ skipping 102 matching lines @@
 ResultCode TargetServicesBase::DuplicateHandle(HANDLE source_handle,
                                                DWORD target_process_id,
                                                HANDLE* target_handle,
                                                DWORD desired_access,
                                                DWORD options) {
   return sandbox::DuplicateHandleProxy(source_handle, target_process_id,
                                        target_handle, desired_access, options);
 }
 
 }  // namespace sandbox