chrome/common/sandbox_policy.cc

   1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/common/sandbox_policy.h"
   6
   7 #include <string>
   8
   9 #include "app/win_util.h"
  10 #include "base/command_line.h"
  11 #include "base/debug_util.h"
  12 #include "base/file_util.h"
  13 #include "base/logging.h"
  14 #include "base/path_service.h"
  15 #include "base/process_util.h"
  16 #include "base/string_util.h"
  17 #include "base/trace_event.h"
  18 #include "base/win_util.h"
  19 #include "chrome/common/child_process_info.h"
  20 #include "chrome/common/chrome_constants.h"
  21 #include "chrome/common/chrome_paths.h"
  22 #include "chrome/common/chrome_switches.h"
  23 #include "chrome/common/debug_flags.h"
  24 #include "sandbox/src/sandbox.h"
  25
  26 static sandbox::BrokerServices* g_broker_services = NULL;
  27
  28 namespace {
  29
  30 // The DLLs listed here are known (or under strong suspicion) of causing crashes
  31 // when they are loaded in the renderer.
  32 const wchar_t* const kTroublesomeDlls[] = {
  33   L"adialhk.dll",                 // Kaspersky Internet Security.
  34   L"acpiz.dll",                   // Unknown.
  35   L"avgrsstx.dll",                // AVG 8.
  36   L"btkeyind.dll",                // Widcomm Bluetooth.
  37   L"cmcsyshk.dll",                // CMC Internet Security.
  38   L"dockshellhook.dll",           // Stardock Objectdock.
  39   L"GoogleDesktopNetwork3.DLL",   // Google Desktop Search v5.
  40   L"fwhook.dll",                  // PC Tools Firewall Plus.
  41   L"hookprocesscreation.dll",     // Blumentals Program protector.
  42   L"hookterminateapis.dll",       // Blumentals and Cyberprinter.
  43   L"hookprintapis.dll",           // Cyberprinter.
  44   L"imon.dll",                    // NOD32 Antivirus.
  45   L"ioloHL.dll",                  // Iolo (System Mechanic).
  46   L"kloehk.dll",                  // Kaspersky Internet Security.
  47   L"lawenforcer.dll",             // Spyware-Browser AntiSpyware (Spybro).
  48   L"libdivx.dll",                 // DivX.
  49   L"lvprcinj01.dll",              // Logitech QuickCam.
  50   L"madchook.dll",                // Madshi (generic hooking library).
  51   L"mdnsnsp.dll",                 // Bonjour.
  52   L"moonsysh.dll",                // Moon Secure Antivirus.
  53   L"npdivx32.dll",                // DivX.
  54   L"npggNT.des",                  // GameGuard 2008.
  55   L"npggNT.dll",                  // GameGuard (older).
  56   L"oawatch.dll",                 // Online Armor.
  57   L"pavhook.dll",                 // Panda Internet Security.
  58   L"pavshook.dll",                // Panda Antivirus.
  59   L"pctavhook.dll",               // PC Tools Antivirus.
  60   L"pctgmhk.dll",                 // PC Tools Spyware Doctor.
  61   L"prntrack.dll",                // Pharos Systems.
  62   L"radhslib.dll",                // Radiant Naomi Internet Filter.
  63   L"radprlib.dll",                // Radiant Naomi Internet Filter.
  64   L"rlhook.dll",                  // Trustware Bufferzone.
  65   L"r3hook.dll",                  // Kaspersky Internet Security.
  66   L"sahook.dll",                  // McAfee Site Advisor.
  67   L"sbrige.dll",                  // Unknown.
  68   L"sc2hook.dll",                 // Supercopier 2.
  69   L"sguard.dll",                  // Iolo (System Guard).
  70   L"smum32.dll",                  // Spyware Doctor version 6.
  71   L"smumhook.dll",                // Spyware Doctor version 5.
  72   L"ssldivx.dll",                 // DivX.
  73   L"syncor11.dll",                // SynthCore Midi interface.
  74   L"systools.dll",                // Panda Antivirus.
  75   L"tfwah.dll",                   // Threatfire (PC tools).
  76   L"wblind.dll",                  // Stardock Object desktop.
  77   L"wbhelp.dll",                  // Stardock Object desktop.
  78   L"winstylerthemehelper.dll"     // Tuneup utilities 2006.
  79 };
  80
  81 enum PluginPolicyCategory {
  82   PLUGIN_GROUP_TRUSTED,
  83   PLUGIN_GROUP_UNTRUSTED,
  84 };
  85
  86 // Returns the policy category for the plugin dll.
  87 PluginPolicyCategory GetPolicyCategoryForPlugin(
  88     const std::wstring& dll,
  89     const std::wstring& list) {
  90   std::wstring filename = FilePath(dll).BaseName().value();
  91   std::wstring plugin_dll = StringToLowerASCII(filename);
  92   std::wstring trusted_plugins = StringToLowerASCII(list);
  93
  94   size_t pos = 0;
  95   size_t end_item = 0;
  96   while (end_item != std::wstring::npos) {
  97     end_item = list.find(L",", pos);
  98
  99     size_t size_item = (end_item == std::wstring::npos) ? end_item :
 100                                                           end_item - pos;
 101     std::wstring item = list.substr(pos, size_item);
 102     if (!item.empty() && item == plugin_dll)
 103       return PLUGIN_GROUP_TRUSTED;
 104
 105     pos = end_item + 1;
 106   }
 107
 108   return PLUGIN_GROUP_UNTRUSTED;
 109 }
 110
 111 // Adds the policy rules for the path and path\ with the semantic |access|.
 112 // If |children| is set to true, we need to add the wildcard rules to also
 113 // apply the rule to the subfiles and subfolders.
 114 bool AddDirectory(int path, const wchar_t* sub_dir, bool children,
 115                   sandbox::TargetPolicy::Semantics access,
 116                   sandbox::TargetPolicy* policy) {
 117   std::wstring directory;
 118   if (!PathService::Get(path, &directory))
 119     return false;
 120
 121   if (sub_dir) {
 122     file_util::AppendToPath(&directory, sub_dir);
 123     file_util::AbsolutePath(&directory);
 124   }
 125
 126   sandbox::ResultCode result;
 127   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_FILES, access,
 128                            directory.c_str());
 129   if (result != sandbox::SBOX_ALL_OK)
 130     return false;
 131
 132   if (children)
 133     file_util::AppendToPath(&directory, L"*");
 134   else
 135     // Add the version of the path that ends with a separator.
 136     file_util::AppendToPath(&directory, L"");
 137
 138   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_FILES, access,
 139                            directory.c_str());
 140   if (result != sandbox::SBOX_ALL_OK)
 141     return false;
 142
 143   return true;
 144 }
 145
 146 // Adds the policy rules for the path and path\* with the semantic |access|.
 147 // We need to add the wildcard rules to also apply the rule to the subkeys.
 148 bool AddKeyAndSubkeys(std::wstring key,
 149                       sandbox::TargetPolicy::Semantics access,
 150                       sandbox::TargetPolicy* policy) {
 151   sandbox::ResultCode result;
 152   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_REGISTRY, access,
 153                            key.c_str());
 154   if (result != sandbox::SBOX_ALL_OK)
 155     return false;
 156
 157   key += L"\\*";
 158   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_REGISTRY, access,
 159                            key.c_str());
 160   if (result != sandbox::SBOX_ALL_OK)
 161     return false;
 162
 163   return true;
 164 }
 165
 166 // Adds policy rules for unloaded the known dlls that cause chrome to crash.
 167 // Eviction of injected DLLs is done by the sandbox so that the injected module
 168 // does not get a chance to execute any code.
 169 void AddDllEvictionPolicy(sandbox::TargetPolicy* policy) {
 170   for (int ix = 0; ix != arraysize(kTroublesomeDlls); ++ix) {
 171     // To minimize the list we only add an unload policy if the dll is also
 172     // loaded in this process. All the injected dlls of interest do this.
 173     if (::GetModuleHandleW(kTroublesomeDlls[ix])) {
 174       LOG(INFO) << "dll to unload found: " << kTroublesomeDlls[ix];
 175       policy->AddDllToUnload(kTroublesomeDlls[ix]);
 176     }
 177   }
 178 }
 179
 180 // Adds the generic policy rules to a sandbox TargetPolicy.
 181 bool AddGenericPolicy(sandbox::TargetPolicy* policy) {
 182   sandbox::ResultCode result;
 183
 184   // Add the policy for the pipes
 185   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_FILES,
 186                            sandbox::TargetPolicy::FILES_ALLOW_ANY,
 187                            L"\\??\\pipe\\chrome.*");
 188   if (result != sandbox::SBOX_ALL_OK)
 189     return false;
 190
 191   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_NAMED_PIPES,
 192                            sandbox::TargetPolicy::NAMEDPIPES_ALLOW_ANY,
 193                            L"\\\\.\\pipe\\chrome.nacl.*");
 194   if (result != sandbox::SBOX_ALL_OK)
 195     return false;
 196
 197   // Add the policy for debug message only in debug
 198 #ifndef NDEBUG
 199   std::wstring debug_message;
 200   if (!PathService::Get(chrome::DIR_APP, &debug_message))
 201     return false;
 202   if (!win_util::ConvertToLongPath(debug_message, &debug_message))
 203     return false;
 204   file_util::AppendToPath(&debug_message, L"debug_message.exe");
 205   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_PROCESS,
 206                            sandbox::TargetPolicy::PROCESS_MIN_EXEC,
 207                            debug_message.c_str());
 208   if (result != sandbox::SBOX_ALL_OK)
 209     return false;
 210 #endif  // NDEBUG
 211
 212   return true;
 213 }
 214
 215 // Creates a sandbox without any restriction.
 216 bool ApplyPolicyForTrustedPlugin(sandbox::TargetPolicy* policy) {
 217   policy->SetJobLevel(sandbox::JOB_UNPROTECTED, 0);
 218   policy->SetTokenLevel(sandbox::USER_UNPROTECTED, sandbox::USER_UNPROTECTED);
 219   return true;
 220 }
 221
 222 // Creates a sandbox with the plugin running in a restricted environment.
 223 // Only the "Users" and "Everyone" groups are enabled in the token. The User SID
 224 // is disabled.
 225 bool ApplyPolicyForUntrustedPlugin(sandbox::TargetPolicy* policy) {
 226   policy->SetJobLevel(sandbox::JOB_UNPROTECTED, 0);
 227
 228   sandbox::TokenLevel initial_token = sandbox::USER_UNPROTECTED;
 229   if (win_util::GetWinVersion() > win_util::WINVERSION_XP) {
 230     // On 2003/Vista the initial token has to be restricted if the main token
 231     // is restricted.
 232     initial_token = sandbox::USER_RESTRICTED_SAME_ACCESS;
 233   }
 234   policy->SetTokenLevel(initial_token, sandbox::USER_LIMITED);
 235   policy->SetDelayedIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
 236
 237   if (!AddDirectory(base::DIR_TEMP, NULL, true,
 238                     sandbox::TargetPolicy::FILES_ALLOW_ANY, policy))
 239     return false;
 240
 241   if (!AddDirectory(base::DIR_IE_INTERNET_CACHE, NULL, true,
 242                     sandbox::TargetPolicy::FILES_ALLOW_ANY, policy))
 243     return false;
 244
 245   if (!AddDirectory(base::DIR_APP_DATA, NULL, true,
 246                     sandbox::TargetPolicy::FILES_ALLOW_READONLY,
 247                     policy))
 248     return false;
 249
 250   if (!AddDirectory(base::DIR_PROFILE, NULL, false,  /*not recursive*/
 251                     sandbox::TargetPolicy::FILES_ALLOW_READONLY,
 252                     policy))
 253     return false;
 254
 255   if (!AddDirectory(base::DIR_APP_DATA, L"Adobe", true,
 256                     sandbox::TargetPolicy::FILES_ALLOW_ANY,
 257                     policy))
 258     return false;
 259
 260   if (!AddDirectory(base::DIR_APP_DATA, L"Macromedia", true,
 261                     sandbox::TargetPolicy::FILES_ALLOW_ANY,
 262                     policy))
 263     return false;
 264
 265   if (!AddDirectory(base::DIR_LOCAL_APP_DATA, NULL, true,
 266                     sandbox::TargetPolicy::FILES_ALLOW_READONLY,
 267                     policy))
 268     return false;
 269
 270   if (!AddKeyAndSubkeys(L"HKEY_CURRENT_USER\\SOFTWARE\\ADOBE",
 271                         sandbox::TargetPolicy::REG_ALLOW_ANY,
 272                         policy))
 273     return false;
 274
 275   if (!AddKeyAndSubkeys(L"HKEY_CURRENT_USER\\SOFTWARE\\MACROMEDIA",
 276                         sandbox::TargetPolicy::REG_ALLOW_ANY,
 277                         policy))
 278     return false;
 279
 280   if (win_util::GetWinVersion() >= win_util::WINVERSION_VISTA) {
 281     if (!AddKeyAndSubkeys(L"HKEY_CURRENT_USER\\SOFTWARE\\AppDataLow",
 282                           sandbox::TargetPolicy::REG_ALLOW_ANY,
 283                           policy))
 284       return false;
 285
 286     if (!AddDirectory(base::DIR_LOCAL_APP_DATA_LOW, NULL, true,
 287                       sandbox::TargetPolicy::FILES_ALLOW_ANY,
 288                       policy))
 289       return false;
 290
 291     // DIR_APP_DATA is AppData\Roaming, but Adobe needs to do a directory
 292     // listing in AppData directly, so we add a non-recursive policy for
 293     // AppData itself.
 294     if (!AddDirectory(base::DIR_APP_DATA, L"..", false,
 295                       sandbox::TargetPolicy::FILES_ALLOW_READONLY,
 296                       policy))
 297       return false;
 298   }
 299
 300   return true;
 301 }
 302
 303 // Creates a sandbox for the built-in flash plugin running in a restricted
 304 // environment. This is a work in progress and for the time being do not
 305 // pay attention to the duplication between this function and the above
 306 // function. For more information see bug 50796.
 307 bool ApplyPolicyForBuiltInFlashPlugin(sandbox::TargetPolicy* policy) {
 308   // TODO(cpu): Lock down the job level more.
 309   policy->SetJobLevel(sandbox::JOB_UNPROTECTED, 0);
 310
 311   sandbox::TokenLevel initial_token = sandbox::USER_UNPROTECTED;
 312   if (win_util::GetWinVersion() > win_util::WINVERSION_XP)
 313     initial_token = sandbox::USER_RESTRICTED_SAME_ACCESS;
 314   policy->SetTokenLevel(initial_token, sandbox::USER_LIMITED);
 315
 316   policy->SetDelayedIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
 317
 318   // TODO(cpu): Proxy registry access and remove these policies.
 319   if (!AddKeyAndSubkeys(L"HKEY_CURRENT_USER\\SOFTWARE\\ADOBE",
 320                         sandbox::TargetPolicy::REG_ALLOW_ANY,
 321                         policy))
 322     return false;
 323
 324   if (!AddKeyAndSubkeys(L"HKEY_CURRENT_USER\\SOFTWARE\\MACROMEDIA",
 325                         sandbox::TargetPolicy::REG_ALLOW_ANY,
 326                         policy))
 327     return false;
 328
 329   // Use a different data folder for flash data. This needs to be
 330   // reverted once we stop the experiments.
 331   FilePath flash_path;
 332   PathService::Get(chrome::DIR_USER_DATA, &flash_path);
 333   flash_path = flash_path.AppendASCII("swflash");
 334   ::SetEnvironmentVariableW(L"CHROME_FLASH_ROOT",
 335                             flash_path.ToWStringHack().c_str());
 336   return true;
 337 }
 338
 339 // Adds the custom policy rules for a given plugin. |trusted_plugins| contains
 340 // the comma separate list of plugin dll names that should not be sandboxed.
 341 bool AddPolicyForPlugin(const CommandLine* cmd_line,
 342                         sandbox::TargetPolicy* policy) {
 343   std::wstring plugin_dll = cmd_line->
 344       GetSwitchValueNative(switches::kPluginPath);
 345   std::wstring trusted_plugins = CommandLine::ForCurrentProcess()->
 346       GetSwitchValueNative(switches::kTrustedPlugins);
 347   // Add the policy for the pipes.
 348   sandbox::ResultCode result = sandbox::SBOX_ALL_OK;
 349   result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_NAMED_PIPES,
 350                            sandbox::TargetPolicy::NAMEDPIPES_ALLOW_ANY,
 351                            L"\\\\.\\pipe\\chrome.*");
 352   if (result != sandbox::SBOX_ALL_OK) {
 353     NOTREACHED();
 354     return false;
 355   }
 356
 357   // The built-in flash gets a custom, more restricted sandbox.
 358   FilePath builtin_flash;
 359   if (PathService::Get(chrome::FILE_FLASH_PLUGIN, &builtin_flash)) {
 360     FilePath plugin_path(plugin_dll);
 361     if (plugin_path == builtin_flash)
 362       return ApplyPolicyForBuiltInFlashPlugin(policy);
 363   }
 364
 365   PluginPolicyCategory policy_category =
 366       GetPolicyCategoryForPlugin(plugin_dll, trusted_plugins);
 367
 368   switch (policy_category) {
 369     case PLUGIN_GROUP_TRUSTED:
 370       return ApplyPolicyForTrustedPlugin(policy);
 371     case PLUGIN_GROUP_UNTRUSTED:
 372       return ApplyPolicyForUntrustedPlugin(policy);
 373     default:
 374       NOTREACHED();
 375       break;
 376   }
 377
 378   return false;
 379 }
 380
 381 void AddPolicyForRenderer(sandbox::TargetPolicy* policy,
 382                           bool* on_sandbox_desktop) {
 383   policy->SetJobLevel(sandbox::JOB_LOCKDOWN, 0);
 384
 385   sandbox::TokenLevel initial_token = sandbox::USER_UNPROTECTED;
 386   if (win_util::GetWinVersion() > win_util::WINVERSION_XP) {
 387     // On 2003/Vista the initial token has to be restricted if the main
 388     // token is restricted.
 389     initial_token = sandbox::USER_RESTRICTED_SAME_ACCESS;
 390   }
 391
 392   policy->SetTokenLevel(initial_token, sandbox::USER_LOCKDOWN);
 393   policy->SetDelayedIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
 394
 395   bool use_winsta = !CommandLine::ForCurrentProcess()->HasSwitch(
 396                         switches::kDisableAltWinstation);
 397
 398   if (sandbox::SBOX_ALL_OK ==  policy->SetAlternateDesktop(use_winsta)) {
 399     *on_sandbox_desktop = true;
 400   } else {
 401     *on_sandbox_desktop = false;
 402     DLOG(WARNING) << "Failed to apply desktop security to the renderer";
 403   }
 404
 405   AddDllEvictionPolicy(policy);
 406 }
 407
 408 }  // namespace
 409
 410 namespace sandbox {
 411
 412 void InitBrokerServices(sandbox::BrokerServices* broker_services) {
 413   // TODO(abarth): DCHECK(CalledOnValidThread());
 414   //               See <http://b/1287166>.
 415   CHECK(broker_services);
 416   CHECK(!g_broker_services);
 417   broker_services->Init();
 418   g_broker_services = broker_services;
 419 }
 420
 421 base::ProcessHandle StartProcessWithAccess(CommandLine* cmd_line,
 422                                            const FilePath& exposed_dir) {
 423   base::ProcessHandle process = 0;
 424   const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
 425   ChildProcessInfo::ProcessType type;
 426   std::string type_str = cmd_line->GetSwitchValueASCII(switches::kProcessType);
 427   if (type_str == switches::kRendererProcess) {
 428     type = ChildProcessInfo::RENDER_PROCESS;
 429   } else if (type_str == switches::kExtensionProcess) {
 430     // Extensions are just renderers with another name.
 431     type = ChildProcessInfo::RENDER_PROCESS;
 432   } else if (type_str == switches::kPluginProcess) {
 433     type = ChildProcessInfo::PLUGIN_PROCESS;
 434   } else if (type_str == switches::kWorkerProcess) {
 435     type = ChildProcessInfo::WORKER_PROCESS;
 436   } else if (type_str == switches::kNaClLoaderProcess) {
 437     type = ChildProcessInfo::NACL_LOADER_PROCESS;
 438   } else if (type_str == switches::kUtilityProcess) {
 439     type = ChildProcessInfo::UTILITY_PROCESS;
 440   } else if (type_str == switches::kNaClBrokerProcess) {
 441     type = ChildProcessInfo::NACL_BROKER_PROCESS;
 442   } else if (type_str == switches::kGpuProcess) {
 443     type = ChildProcessInfo::GPU_PROCESS;
 444   } else {
 445     NOTREACHED();
 446     return 0;
 447   }
 448
 449   TRACE_EVENT_BEGIN("StartProcessWithAccess", 0, type_str);
 450
 451   bool in_sandbox =
 452       (type != ChildProcessInfo::NACL_BROKER_PROCESS) &&
 453       !browser_command_line.HasSwitch(switches::kNoSandbox) &&
 454       (type != ChildProcessInfo::PLUGIN_PROCESS ||
 455        browser_command_line.HasSwitch(switches::kSafePlugins)) &&
 456       (type != ChildProcessInfo::GPU_PROCESS);
 457 #if !defined (GOOGLE_CHROME_BUILD)
 458   if (browser_command_line.HasSwitch(switches::kInProcessPlugins)) {
 459     // In process plugins won't work if the sandbox is enabled.
 460     in_sandbox = false;
 461   }
 462 #endif
 463   if (!browser_command_line.HasSwitch(switches::kDisableExperimentalWebGL) &&
 464       browser_command_line.HasSwitch(switches::kInProcessWebGL)) {
 465     // In process WebGL won't work if the sandbox is enabled.
 466     in_sandbox = false;
 467   }
 468
 469   // Propagate the Chrome Frame flag to sandboxed processes if present.
 470   if (browser_command_line.HasSwitch(switches::kChromeFrame)) {
 471     if (!cmd_line->HasSwitch(switches::kChromeFrame)) {
 472       cmd_line->AppendSwitch(switches::kChromeFrame);
 473     }
 474   }
 475
 476   bool child_needs_help =
 477       DebugFlags::ProcessDebugFlags(cmd_line, type, in_sandbox);
 478
 479   // Prefetch hints on windows:
 480   // Using a different prefetch profile per process type will allow Windows
 481   // to create separate pretetch settings for browser, renderer etc.
 482   cmd_line->AppendArg(StringPrintf("/prefetch:%d", type));
 483
 484   if (!in_sandbox) {
 485     base::LaunchApp(*cmd_line, false, false, &process);
 486     return process;
 487   }
 488
 489   sandbox::ResultCode result;
 490   PROCESS_INFORMATION target = {0};
 491   sandbox::TargetPolicy* policy = g_broker_services->CreatePolicy();
 492
 493   bool on_sandbox_desktop = false;
 494   if (type == ChildProcessInfo::PLUGIN_PROCESS) {
 495     if (!AddPolicyForPlugin(cmd_line, policy))
 496       return 0;
 497   } else {
 498     AddPolicyForRenderer(policy, &on_sandbox_desktop);
 499
 500     if (type_str != switches::kRendererProcess) {
 501       // Hack for Google Desktop crash. Trick GD into not injecting its DLL into
 502       // this subprocess. See
 503       // http://code.google.com/p/chromium/issues/detail?id=25580
 504       cmd_line->AppendSwitchASCII("ignored", " --type=renderer ");
 505     }
 506   }
 507
 508   if (!exposed_dir.empty()) {
 509     result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_FILES,
 510                              sandbox::TargetPolicy::FILES_ALLOW_ANY,
 511                              exposed_dir.ToWStringHack().c_str());
 512     if (result != sandbox::SBOX_ALL_OK)
 513       return 0;
 514
 515     FilePath exposed_files = exposed_dir.AppendASCII("*");
 516     result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_FILES,
 517                              sandbox::TargetPolicy::FILES_ALLOW_ANY,
 518                              exposed_files.ToWStringHack().c_str());
 519     if (result != sandbox::SBOX_ALL_OK)
 520       return 0;
 521   }
 522
 523   if (!AddGenericPolicy(policy)) {
 524     NOTREACHED();
 525     return 0;
 526   }
 527
 528   TRACE_EVENT_BEGIN("StartProcessWithAccess::LAUNCHPROCESS", 0, 0);
 529
 530   result = g_broker_services->SpawnTarget(
 531       cmd_line->program().c_str(),
 532       cmd_line->command_line_string().c_str(),
 533       policy, &target);
 534   policy->Release();
 535
 536   TRACE_EVENT_END("StartProcessWithAccess::LAUNCHPROCESS", 0, 0);
 537
 538   if (sandbox::SBOX_ALL_OK != result)
 539     return 0;
 540
 541   ResumeThread(target.hThread);
 542   CloseHandle(target.hThread);
 543   process = target.hProcess;
 544
 545   // Help the process a little. It can't start the debugger by itself if
 546   // the process is in a sandbox.
 547   if (child_needs_help)
 548     DebugUtil::SpawnDebuggerOnProcess(target.dwProcessId);
 549
 550   return process;
 551 }
 552
 553 }  // namespace sandbox