// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "sandbox/policy/win/sandbox_win.h"
#include <windows.h>
#include <stddef.h>
#include <winternl.h>
#include <map>
#include <optional>
#include <sstream>
#include <string>
#include <string_view>
#include <utility>
#include <vector>
#include "base/command_line.h"
#include "base/containers/contains.h"
#include "base/feature_list.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/hash/hash.h"
#include "base/hash/sha1.h"
#include "base/logging.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/histogram_macros.h"
#include "base/metrics/metrics_hashes.h"
#include "base/no_destructor.h"
#include "base/path_service.h"
#include "base/process/launch.h"
#include "base/process/process.h"
#include "base/strings/strcat.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "base/strings/string_util_win.h"
#include "base/strings/utf_string_conversions.h"
#include "base/system/sys_info.h"
#include "base/task/sequenced_task_runner.h"
#include "base/task/thread_pool.h"
#include "base/time/time.h"
#include "base/trace_event/trace_event.h"
#include "base/win/iat_patch_function.h"
#include "base/win/scoped_handle.h"
#include "base/win/scoped_process_information.h"
#include "base/win/security_util.h"
#include "base/win/sid.h"
#include "base/win/win_util.h"
#include "base/win/windows_version.h"
#include "build/build_config.h"
#include "ppapi/buildflags/buildflags.h"
#include "printing/buildflags/buildflags.h"
#include "sandbox/features.h"
#include "sandbox/policy/features.h"
#include "sandbox/policy/mojom/sandbox.mojom.h"
#include "sandbox/policy/sandbox_type.h"
#include "sandbox/policy/switches.h"
#include "sandbox/policy/win/lpac_capability.h"
#include "sandbox/policy/win/sandbox_diagnostics.h"
#include "sandbox/win/src/app_container.h"
#include "sandbox/win/src/process_mitigations.h"
#include "sandbox/win/src/sandbox.h"
#include "services/screen_ai/buildflags/buildflags.h"
namespace sandbox {
namespace policy {
using sandbox::mojom::Sandbox;
namespace {
BrokerServices* g_broker_services = NULL;
// The DLLs listed here are known (or under strong suspicion) of causing crashes
// when they are loaded in the renderer. Note: at runtime we generate short
// versions of the dll name only if the dll has an extension.
// For more information about how this list is generated, and how to get off
// of it, see:
// https://sites.google.com/a/chromium.org/dev/Home/third-party-developers
const wchar_t* const kTroublesomeDlls[] = {
L"btkeyind.dll", // Widcomm Bluetooth.
L"dockshellhook.dll", // Stardock Objectdock.
L"easyhook32.dll", // GDIPP and others.
L"easyhook64.dll", // Symantec BlueCoat and others.
L"guard64.dll", // Comodo Internet Security x64.
L"mdnsnsp.dll", // Bonjour.
L"n64hooks.dll", // Neilsen//NetRatings NetSight.
L"pmls64.dll", // PremierOpinion and Relevant-Knowledge.
L"prochook.dll", // Unknown (GBill-Tools?) (crbug.com/974722).
L"rlls.dll", // PremierOpinion and Relevant-Knowledge.
L"rlls64.dll", // PremierOpinion and Relevant-Knowledge.
L"rpchromebrowserrecordhelper.dll", // RealPlayer.
};
// This is for finch. See also crbug.com/464430 for details.
BASE_FEATURE(kEnableCsrssLockdownFeature,
"EnableCsrssLockdown",
base::FEATURE_DISABLED_BY_DEFAULT);
// Adds the policy rules to allow read-only access to the windows system fonts
// directory, and any subdirectories. Used by PDF renderers.
bool AddWindowsFontsDir(TargetConfig* config) {
DCHECK(!config->IsConfigured());
base::FilePath directory;
if (!base::PathService::Get(base::DIR_WINDOWS_FONTS, &directory)) {
return false;
}
ResultCode result = config->AllowFileAccess(FileSemantics::kAllowReadonly,
directory.value().c_str());
if (result != SBOX_ALL_OK)
return false;
std::wstring directory_str = directory.value() + L"\\*";
result = config->AllowFileAccess(FileSemantics::kAllowReadonly,
directory_str.c_str());
if (result != SBOX_ALL_OK)
return false;
return true;
}
// Return a mapping between the long and short names for all loaded modules in
// the current process. The mapping excludes modules which don't have a typical
// short name, e.g. EXAMPL~1.DLL.
std::map<std::wstring, std::wstring> GetShortNameModules() {
std::vector<HMODULE> modules;
if (!base::win::GetLoadedModulesSnapshot(::GetCurrentProcess(), &modules)) {
return {};
}
std::map<std::wstring, std::wstring> names;
for (HMODULE module : modules) {
wchar_t path[MAX_PATH];
DWORD sz = ::GetModuleFileNameW(module, path, std::size(path));
if ((sz == std::size(path)) || (sz == 0)) {
continue;
}
base::FilePath module_path(path);
base::FilePath name = module_path.BaseName();
if (name.RemoveExtension().value().size() > 8 ||
name.Extension().size() > 4 || !base::Contains(name.value(), L"~")) {
continue;
}
base::FilePath fname = base::MakeLongFilePath(module_path);
names.insert_or_assign(base::ToLowerASCII(fname.BaseName().value()),
name.value());
}
return names;
}
// Add a block list DLL to a configuration |config| based on the name of the DLL
// passed as |module_name|. The DLL must be loaded in the current process. A
// mapping from long names to short names should also be passed in |modules| to
// attempt to map a long name to the actual loaded name, this can be initialized
// with a call to GetShortNameModules. Returns true if the DLL is loaded and
// will be blocked in the child.
bool BlocklistAddOneDll(const wchar_t* module_name,
const std::map<std::wstring, std::wstring>& modules,
TargetConfig* config) {
DCHECK(!config->IsConfigured());
if (::GetModuleHandleW(module_name) != nullptr) {
config->AddDllToUnload(module_name);
DVLOG(1) << "dll to unload found: " << module_name;
return true;
} else {
auto short_name = modules.find(base::ToLowerASCII(module_name));
if (short_name != modules.end()) {
config->AddDllToUnload(short_name->second.c_str());
config->AddDllToUnload(module_name);
return true;
}
}
return false;
}
// Adds the generic config rules to a sandbox TargetConfig.
ResultCode AddGenericConfig(sandbox::TargetConfig* config) {
DCHECK(!config->IsConfigured());
// Add the policy for read-only PDB file access for stack traces.
#if !defined(OFFICIAL_BUILD)
base::FilePath exe;
if (!base::PathService::Get(base::FILE_EXE, &exe))
return SBOX_ERROR_GENERIC;
base::FilePath pdb_path = exe.DirName().Append(L"*.pdb");
{
ResultCode result = config->AllowFileAccess(FileSemantics::kAllowReadonly,
pdb_path.value().c_str());
if (result != SBOX_ALL_OK) {
return result;
}
}
#endif
#if defined(SANITIZER_COVERAGE)
DWORD coverage_dir_size =
::GetEnvironmentVariable(L"SANITIZER_COVERAGE_DIR", NULL, 0);
if (coverage_dir_size == 0) {
LOG(WARNING) << "SANITIZER_COVERAGE_DIR was not set, coverage won't work.";
} else {
std::wstring coverage_dir;
wchar_t* coverage_dir_str =
base::WriteInto(&coverage_dir, coverage_dir_size);
coverage_dir_size = ::GetEnvironmentVariable(
L"SANITIZER_COVERAGE_DIR", coverage_dir_str, coverage_dir_size);
CHECK(coverage_dir.size() == coverage_dir_size);
base::FilePath sancov_path =
base::FilePath(coverage_dir).Append(L"*.sancov");
{
ResultCode result = config->AllowFileAccess(FileSemantics::kAllowAny,
sancov_path.value().c_str());
if (result != SBOX_ALL_OK) {
return result;
}
}
}
#endif
std::map<std::wstring, std::wstring> modules = GetShortNameModules();
// Adds policy rules for unloading the known dlls that cause Chrome to crash.
// Eviction of injected DLLs is done by the sandbox so that the injected
// module does not get a chance to execute any code.
for (const wchar_t* blocklist_dll : kTroublesomeDlls) {
if (BlocklistAddOneDll(blocklist_dll, modules, config)) {
// Log the module to help with list cleanup.
base::UmaHistogramSparse("Process.Sandbox.DllBlocked",
static_cast<int32_t>(base::HashMetricName(
base::WideToASCII(blocklist_dll))));
}
}
return SBOX_ALL_OK;
}
ResultCode AddDefaultConfigForSandboxedProcess(TargetConfig* config) {
// Prevents the renderers from manipulating low-integrity processes.
config->SetDelayedIntegrityLevel(INTEGRITY_LEVEL_UNTRUSTED);
ResultCode result = config->SetIntegrityLevel(INTEGRITY_LEVEL_LOW);
if (result != SBOX_ALL_OK)
return result;
// The initial token has to be restricted if the main token is restricted.
result = config->SetTokenLevel(USER_RESTRICTED_SAME_ACCESS, USER_LOCKDOWN);
if (result != SBOX_ALL_OK)
return result;
config->SetLockdownDefaultDacl();
config->AddKernelObjectToClose(HandleToClose::kDeviceApi);
config->SetDesktop(Desktop::kAlternateWinstation);
return SBOX_ALL_OK;
}
// This code is test only, and attempts to catch unsafe uses of
// DuplicateHandle() that copy privileged handles into sandboxed processes.
#if !defined(OFFICIAL_BUILD) && !defined(COMPONENT_BUILD)
base::win::IATPatchFunction& GetIATPatchFunctionHandle() {
static base::NoDestructor<base::win::IATPatchFunction>
iat_patch_duplicate_handle;
return *iat_patch_duplicate_handle;
}
using DuplicateHandleFunctionPtr = decltype(::DuplicateHandle)*;
DuplicateHandleFunctionPtr g_iat_orig_duplicate_handle;
static const char* kDuplicateHandleWarning =
"You are attempting to duplicate a privileged handle into a sandboxed"
" process.\n Please contact [email protected] for assistance.";
void CheckDuplicateHandle(HANDLE handle) {
// Get the object type (32 characters is safe; current max is 14).
BYTE buffer[sizeof(PUBLIC_OBJECT_TYPE_INFORMATION) + 32 * sizeof(wchar_t)];
PPUBLIC_OBJECT_TYPE_INFORMATION type_info =
reinterpret_cast<PPUBLIC_OBJECT_TYPE_INFORMATION>(buffer);
ULONG size = sizeof(buffer);
NTSTATUS error =
::NtQueryObject(handle, ObjectTypeInformation, type_info, size, &size);
CHECK(NT_SUCCESS(error));
std::wstring_view type_name(type_info->TypeName.Buffer,
type_info->TypeName.Length / sizeof(wchar_t));
std::optional<ACCESS_MASK> granted_access =
base::win::GetGrantedAccess(handle);
CHECK(granted_access.has_value());
CHECK(!(*granted_access & WRITE_DAC)) << kDuplicateHandleWarning;
if (base::EqualsCaseInsensitiveASCII(type_name, L"Process")) {
const ACCESS_MASK kDangerousMask =
~static_cast<DWORD>(PROCESS_QUERY_LIMITED_INFORMATION | SYNCHRONIZE);
CHECK(!(*granted_access & kDangerousMask)) << kDuplicateHandleWarning;
}
}
BOOL WINAPI DuplicateHandlePatch(HANDLE source_process_handle,
HANDLE source_handle,
HANDLE target_process_handle,
LPHANDLE target_handle,
DWORD desired_access,
BOOL inherit_handle,
DWORD options) {
// Duplicate the handle so we get the final access mask.
if (!g_iat_orig_duplicate_handle(source_process_handle, source_handle,
target_process_handle, target_handle,
desired_access, inherit_handle, options))
return FALSE;
// We're not worried about broker handles or not crossing process boundaries.
if (source_process_handle == target_process_handle ||
target_process_handle == ::GetCurrentProcess())
return TRUE;
// Only sandboxed children are placed in jobs, so just check them.
BOOL is_in_job = FALSE;
if (!::IsProcessInJob(target_process_handle, NULL, &is_in_job)) {
// We need a handle with permission to check the job object.
if (ERROR_ACCESS_DENIED == ::GetLastError()) {
HANDLE temp_handle;
CHECK(g_iat_orig_duplicate_handle(
::GetCurrentProcess(), target_process_handle, ::GetCurrentProcess(),
&temp_handle, PROCESS_QUERY_INFORMATION, FALSE, 0));
base::win::ScopedHandle process(temp_handle);
CHECK(::IsProcessInJob(process.Get(), NULL, &is_in_job));
}
}
if (is_in_job) {
// We never allow inheritable child handles.
CHECK(!inherit_handle) << kDuplicateHandleWarning;
// Duplicate the handle again, to get the final permissions.
HANDLE temp_handle;
CHECK(g_iat_orig_duplicate_handle(target_process_handle, *target_handle,
::GetCurrentProcess(), &temp_handle, 0,
FALSE, DUPLICATE_SAME_ACCESS));
base::win::ScopedHandle handle(temp_handle);
// Callers use CHECK macro to make sure we get the right stack.
CheckDuplicateHandle(handle.Get());
}
return TRUE;
}
#endif
bool IsAppContainerEnabled() {
if (!sandbox::features::IsAppContainerSandboxSupported())
return false;
return base::FeatureList::IsEnabled(features::kRendererAppContainer);
}
// Generate a unique sandbox AC profile for the appcontainer based on the SHA1
// hash of the appcontainer_id. This does not need to be secure so using SHA1
// isn't a security concern.
std::wstring GetAppContainerProfileName(const std::string& appcontainer_id,
Sandbox sandbox_type) {
std::string sandbox_base_name;
switch (sandbox_type) {
case Sandbox::kXrCompositing:
sandbox_base_name = std::string("cr.sb.xr");
break;
case Sandbox::kGpu:
sandbox_base_name = std::string("cr.sb.gpu");
break;
case Sandbox::kMediaFoundationCdm:
sandbox_base_name = std::string("cr.sb.cdm");
break;
case Sandbox::kNetwork:
sandbox_base_name = std::string("cr.sb.net");
break;
case Sandbox::kOnDeviceModelExecution:
sandbox_base_name = std::string("cr.sb.odm");
break;
#if BUILDFLAG(ENABLE_PRINTING)
case Sandbox::kPrintCompositor:
sandbox_base_name = std::string("cr.sb.prnc");
break;
#endif
case Sandbox::kWindowsSystemProxyResolver:
sandbox_base_name = std::string("cr.sb.pxy");
break;
default:
DCHECK(0);
}
auto sha1 = base::SHA1HashString(appcontainer_id);
std::string profile_name =
base::StrCat({sandbox_base_name, base::HexEncode(sha1)});
// CreateAppContainerProfile requires that the profile name is at most 64
// characters but 50 on WCOS systems. The size of sha1 is a constant 40,
// so validate that the base names are sufficiently short that the total
// length is valid on all systems.
DCHECK_LE(profile_name.length(), 50U);
return base::UTF8ToWide(profile_name);
}
void AddCapabilitiesFromString(AppContainer* container,
const std::wstring& caps) {
for (const std::wstring& cap : base::SplitString(
caps, L",", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY)) {
container->AddCapability(cap.c_str());
}
}
ResultCode SetupAppContainerProfile(AppContainer* container,
const base::CommandLine& command_line,
Sandbox sandbox_type) {
if (sandbox_type != Sandbox::kGpu &&
sandbox_type != Sandbox::kXrCompositing &&
sandbox_type != Sandbox::kMediaFoundationCdm &&
sandbox_type != Sandbox::kNetwork &&
sandbox_type != Sandbox::kOnDeviceModelExecution &&
#if BUILDFLAG(ENABLE_PRINTING)
!(sandbox_type == Sandbox::kPrintCompositor &&
base::FeatureList::IsEnabled(
sandbox::policy::features::kPrintCompositorLPAC)) &&
#endif
sandbox_type != Sandbox::kWindowsSystemProxyResolver) {
return SBOX_ERROR_UNSUPPORTED;
}
container->AddCapability(kLpacChromeInstallFiles);
container->AddCapability(kRegistryRead);
if (sandbox_type == Sandbox::kGpu) {
container->AddImpersonationCapability(kChromeInstallFiles);
container->AddCapability(kLpacPnpNotifications);
AddCapabilitiesFromString(
container,
command_line.GetSwitchValueNative(switches::kAddGpuAppContainerCaps));
container->SetEnableLowPrivilegeAppContainer(
base::FeatureList::IsEnabled(features::kGpuLPAC));
}
if (sandbox_type == Sandbox::kXrCompositing) {
container->AddCapability(kChromeInstallFiles);
container->AddCapability(kLpacPnpNotifications);
AddCapabilitiesFromString(container, command_line.GetSwitchValueNative(
switches::kAddXrAppContainerCaps));
// Note: does not use LPAC.
}
if (sandbox_type == Sandbox::kMediaFoundationCdm) {
// Please refer to the following design doc on why we add the capabilities:
// https://docs.google.com/document/d/19Y4Js5v3BlzA5uSuiVTvcvPNIOwmxcMSFJWtuc1A-w8/edit#heading=h.iqvhsrml3gl9
container->AddCapability(
base::win::WellKnownCapability::kPrivateNetworkClientServer);
container->AddCapability(base::win::WellKnownCapability::kInternetClient);
container->AddCapability(kLpacCom);
container->AddCapability(kLpacIdentityServices);
container->AddCapability(kLpacMedia);
container->AddCapability(kLpacPnPNotifications);
container->AddCapability(kLpacServicesManagement);
container->AddCapability(kLpacSessionManagement);
container->AddCapability(kLpacAppExperience);
container->AddCapability(kLpacInstrumentation);
container->AddCapability(kLpacCryptoServices);
container->AddCapability(kLpacEnterprisePolicyChangeNotifications);
container->AddCapability(kMediaFoundationCdmFiles);
container->AddCapability(kMediaFoundationCdmData);
container->SetEnableLowPrivilegeAppContainer(true);
}
if (sandbox_type == Sandbox::kNetwork) {
container->AddCapability(
base::win::WellKnownCapability::kPrivateNetworkClientServer);
container->AddCapability(base::win::WellKnownCapability::kInternetClient);
container->AddCapability(
base::win::WellKnownCapability::kEnterpriseAuthentication);
container->AddCapability(kLpacIdentityServices);
container->AddCapability(kLpacCryptoServices);
container->SetEnableLowPrivilegeAppContainer(base::FeatureList::IsEnabled(
features::kWinSboxNetworkServiceSandboxIsLPAC));
}
if (sandbox_type == Sandbox::kOnDeviceModelExecution) {
container->AddImpersonationCapability(kChromeInstallFiles);
container->AddCapability(kLpacPnpNotifications);
container->SetEnableLowPrivilegeAppContainer(true);
}
#if BUILDFLAG(ENABLE_PRINTING)
if (sandbox_type == Sandbox::kPrintCompositor) {
container->AddCapability(kLpacCom);
container->AddCapability(L"lpacPrinting");
container->SetEnableLowPrivilegeAppContainer(true);
}
#endif
if (sandbox_type == Sandbox::kWindowsSystemProxyResolver) {
container->AddCapability(base::win::WellKnownCapability::kInternetClient);
container->AddCapability(kLpacServicesManagement);
container->AddCapability(kLpacEnterprisePolicyChangeNotifications);
container->SetEnableLowPrivilegeAppContainer(true);
}
return SBOX_ALL_OK;
}
ResultCode GenerateConfigForSandboxedProcess(const base::CommandLine& cmd_line,
SandboxDelegate* delegate,
TargetConfig* config) {
DCHECK(!config->IsConfigured());
// Pre-startup mitigations.
MitigationFlags mitigations =
MITIGATION_HEAP_TERMINATE | MITIGATION_BOTTOM_UP_ASLR | MITIGATION_DEP |
MITIGATION_DEP_NO_ATL_THUNK | MITIGATION_EXTENSION_POINT_DISABLE |
MITIGATION_SEHOP | MITIGATION_NONSYSTEM_FONT_DISABLE |
MITIGATION_IMAGE_LOAD_NO_REMOTE | MITIGATION_IMAGE_LOAD_NO_LOW_LABEL |
MITIGATION_RESTRICT_INDIRECT_BRANCH_PREDICTION |
MITIGATION_KTM_COMPONENT | MITIGATION_FSCTL_DISABLED;
// CET is enabled with the CETCOMPAT bit on chrome.exe so must be
// disabled for processes we know are not compatible.
if (!delegate->CetCompatible())
mitigations |= MITIGATION_CET_DISABLED;
Sandbox sandbox_type = delegate->GetSandboxType();
if (sandbox_type == Sandbox::kRenderer &&
base::FeatureList::IsEnabled(
sandbox::policy::features::kWinSboxRestrictCoreSharingOnRenderer)) {
mitigations |= MITIGATION_RESTRICT_CORE_SHARING;
}
ResultCode result = config->SetProcessMitigations(mitigations);
if (result != SBOX_ALL_OK)
return result;
// Post-startup mitigations.
mitigations = MITIGATION_DLL_SEARCH_ORDER;
if (!cmd_line.HasSwitch(switches::kAllowThirdPartyModules) &&
#if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
sandbox_type != Sandbox::kScreenAI &&
#endif
sandbox_type != Sandbox::kSpeechRecognition &&
sandbox_type != Sandbox::kMediaFoundationCdm) {
mitigations |= MITIGATION_FORCE_MS_SIGNED_BINS;
}
if (sandbox_type == Sandbox::kNetwork || sandbox_type == Sandbox::kAudio ||
sandbox_type == Sandbox::kIconReader) {
mitigations |= MITIGATION_DYNAMIC_CODE_DISABLE;
}
result = config->SetDelayedProcessMitigations(mitigations);
if (result != SBOX_ALL_OK)
return result;
if (sandbox_type == Sandbox::kRenderer) {
// TODO(crbug.com/40088338) Remove if we can reliably not load
// cryptbase.dll.
config->AddKernelObjectToClose(HandleToClose::kKsecDD);
result = SandboxWin::AddWin32kLockdownPolicy(config);
if (result != SBOX_ALL_OK) {
return result;
}
}
if (!delegate->DisableDefaultPolicy()) {
result = AddDefaultConfigForSandboxedProcess(config);
if (result != SBOX_ALL_OK)
return result;
}
// Disable apphelp for tightly sandboxed processes that are not running
// in WoW or ARM64 emulated modes.
if (sandbox_type == Sandbox::kRenderer || sandbox_type == Sandbox::kService) {
if (base::FeatureList::IsEnabled(
sandbox::policy::features::kWinSboxZeroAppShim) &&
base::win::OSInfo::GetInstance()->IsWowDisabled() &&
!base::win::OSInfo::IsRunningEmulatedOnArm64()) {
config->SetZeroAppShim();
}
}
result =
SandboxWin::SetJobLevel(sandbox_type, JobLevel::kLockdown, 0, config);
if (result != SBOX_ALL_OK)
return result;
if (sandbox_type == Sandbox::kGpu) {
config->SetLockdownDefaultDacl();
config->AddRestrictingRandomSid();
}
if (delegate->AllowWindowsFontsDir()) {
AddWindowsFontsDir(config);
}
result = AddGenericConfig(config);
if (result != SBOX_ALL_OK) {
NOTREACHED_IN_MIGRATION();
return result;
}
std::string appcontainer_id;
if (SandboxWin::IsAppContainerEnabledForSandbox(cmd_line, sandbox_type) &&
delegate->GetAppContainerId(&appcontainer_id)) {
result = SandboxWin::AddAppContainerProfileToConfig(
cmd_line, sandbox_type, appcontainer_id, config);
DCHECK_EQ(result, SBOX_ALL_OK);
if (result != SBOX_ALL_OK)
return result;
}
if (sandbox_type == Sandbox::kMediaFoundationCdm) {
// Set a policy that would normally allow for process creation. This allows
// the mf cdm process to launch the protected media pipeline process
// (mfpmp.exe) without process interception.
result = config->SetJobLevel(JobLevel::kInteractive, 0);
if (result != SBOX_ALL_OK)
return result;
}
if (!delegate->InitializeConfig(config)) {
return SBOX_ERROR_DELEGATE_INITIALIZE_CONFIG;
}
return SBOX_ALL_OK;
}
// Create the job object for unsandboxed processes.
base::win::ScopedHandle CreateUnsandboxedJob() {
base::win::ScopedHandle job(::CreateJobObject(nullptr, nullptr));
if (!job.is_valid()) {
return base::win::ScopedHandle();
}
JOBOBJECT_EXTENDED_LIMIT_INFORMATION limits = {};
limits.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE;
if (!::SetInformationJobObject(job.get(), JobObjectExtendedLimitInformation,
&limits, sizeof(limits))) {
return base::win::ScopedHandle();
}
return job;
}
// Launches outside of the sandbox - the process will not be associated with
// a Policy or TargetProcess. This supports both kNoSandbox and the --no-sandbox
// command line flag.
ResultCode LaunchWithoutSandbox(
const base::CommandLine& cmd_line,
const base::HandlesToInheritVector& handles_to_inherit,
SandboxDelegate* delegate,
base::Process* process) {
base::LaunchOptions options;
options.handles_to_inherit = handles_to_inherit;
// Network process runs in a job even when unsandboxed. This is to ensure it
// does not outlive the browser, which could happen if there is a lot of I/O
// on process shutdown, in which case TerminateProcess can fail. See
// https://crbug.com/820996.
if (delegate->ShouldUnsandboxedRunInJob()) {
static base::NoDestructor<base::win::ScopedHandle> job_object(
CreateUnsandboxedJob());
if (!job_object->is_valid()) {
return SBOX_ERROR_CANNOT_INIT_JOB;
}
options.job_handle = job_object->get();
}
// Chromium binaries are marked as CET Compatible but some processes
// are not. When --no-sandbox is specified we disable CET for all children.
// Otherwise we are here because the sandbox type is kNoSandbox, and allow
// the process delegate to indicate if it is compatible with CET.
if (cmd_line.HasSwitch(switches::kNoSandbox) ||
base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kNoSandbox)) {
options.disable_cetcompat = true;
} else if (!delegate->CetCompatible()) {
options.disable_cetcompat = true;
}
*process = base::LaunchProcess(cmd_line, options);
if (!process->IsValid())
return SBOX_ERROR_CANNOT_LAUNCH_UNSANDBOXED_PROCESS;
return SBOX_ALL_OK;
}
bool IsUnsandboxedProcess(
Sandbox sandbox_type,
const base::CommandLine& cmd_line,
const base::CommandLine& launcher_process_command_line) {
if (IsUnsandboxedSandboxType(sandbox_type))
return true;
if (cmd_line.HasSwitch(switches::kNoSandbox))
return true;
if (launcher_process_command_line.HasSwitch(switches::kNoSandbox))
return true;
return false;
}
} // namespace
void SandboxLaunchTimer::RecordHistograms() {
// If these parameters change the histograms should be renamed.
// We're interested in the happy fast case so have a low maximum.
const auto kLowBound = base::Microseconds(5);
const auto kHighBound = base::Microseconds(100000);
const int kBuckets = 50;
base::UmaHistogramCustomMicrosecondsTimes(
"Process.Sandbox.StartSandboxedWin.CreatePolicyDuration", policy_created_,
kLowBound, kHighBound, kBuckets);
base::UmaHistogramCustomMicrosecondsTimes(
"Process.Sandbox.StartSandboxedWin.GeneratePolicyDuration",
policy_generated_ - policy_created_, kLowBound, kHighBound, kBuckets);
base::UmaHistogramCustomMicrosecondsTimes(
"Process.Sandbox.StartSandboxedWin.SpawnTargetDuration",
process_spawned_ - policy_generated_, kLowBound, kHighBound, kBuckets);
base::UmaHistogramCustomMicrosecondsTimes(
"Process.Sandbox.StartSandboxedWin.PostSpawnTargetDuration",
process_resumed_ - process_spawned_, kLowBound, kHighBound, kBuckets);
base::UmaHistogramCustomMicrosecondsTimes(
"Process.Sandbox.StartSandboxedWin.TotalDuration", process_resumed_,
kLowBound, kHighBound, kBuckets);
}
// static
ResultCode SandboxWin::SetJobLevel(Sandbox sandbox_type,
JobLevel job_level,
uint32_t ui_exceptions,
TargetConfig* config) {
DCHECK(!config->IsConfigured());
ResultCode ret = config->SetJobLevel(job_level, ui_exceptions);
if (ret != SBOX_ALL_OK)
return ret;
std::optional<size_t> memory_limit = GetJobMemoryLimit(sandbox_type);
if (memory_limit) {
config->SetJobMemoryLimit(*memory_limit);
}
return SBOX_ALL_OK;
}
// static
void SandboxWin::AddBaseHandleClosePolicy(TargetConfig* config) {
DCHECK(!config->IsConfigured());
if (base::FeatureList::IsEnabled(kEnableCsrssLockdownFeature)) {
// Close all ALPC ports.
config->SetDisconnectCsrss();
}
config->AddKernelObjectToClose(HandleToClose::kWindowsShellGlobalCounters);
}
// static
ResultCode SandboxWin::AddAppContainerPolicy(TargetConfig* config,
const wchar_t* sid) {
DCHECK(!config->IsConfigured());
if (IsAppContainerEnabled()) {
ResultCode result = config->SetLowBox(sid);
if (result != SBOX_ALL_OK) {
return result;
}
config->GetAppContainer()->AddImpersonationCapability(
kLpacChromeInstallFiles);
}
return SBOX_ALL_OK;
}
// static
ResultCode SandboxWin::AddWin32kLockdownPolicy(TargetConfig* config) {
DCHECK(!config->IsConfigured());
MitigationFlags flags = config->GetProcessMitigations();
// Check not enabling twice. Should not happen.
DCHECK_EQ(0U, flags & MITIGATION_WIN32K_DISABLE);
flags |= MITIGATION_WIN32K_DISABLE;
ResultCode result = config->SetProcessMitigations(flags);
if (result != SBOX_ALL_OK)
return result;
// winmm.dll, used by timeGetTime, depends on user32 and gdi32 until RS1.
if (base::win::GetVersion() <= base::win::Version::WIN10_TH2 ||
!base::FeatureList::IsEnabled(features::kWinSboxNoFakeGdiInit)) {
return config->SetFakeGdiInit();
}
return SBOX_ALL_OK;
}
// static
ResultCode SandboxWin::AddAppContainerProfileToConfig(
const base::CommandLine& command_line,
Sandbox sandbox_type,
const std::string& appcontainer_id,
TargetConfig* config) {
DCHECK(!config->IsConfigured());
if (base::win::GetVersion() < base::win::Version::WIN10_RS1)
return SBOX_ALL_OK;
std::wstring profile_name =
GetAppContainerProfileName(appcontainer_id, sandbox_type);
const ACProfileRegistration registration =
base::FeatureList::IsEnabled(features::kWinSboxACProfileWithoutFirewall)
? ACProfileRegistration::kNoFirewall
: ACProfileRegistration::kDefault;
ResultCode result =
config->AddAppContainerProfile(profile_name.c_str(), registration);
if (result != SBOX_ALL_OK)
return result;
result = SetupAppContainerProfile(config->GetAppContainer(), command_line,
sandbox_type);
if (result != SBOX_ALL_OK)
return result;
DWORD granted_access;
BOOL granted_access_status;
bool access_check =
config->GetAppContainer()->AccessCheck(
command_line.GetProgram().value().c_str(),
base::win::SecurityObjectType::kFile, GENERIC_READ | GENERIC_EXECUTE,
&granted_access, &granted_access_status) &&
granted_access_status;
if (!access_check) {
PLOG(ERROR) << "Sandbox cannot access executable. Check filesystem "
"permissions are valid. See https://bit.ly/31yqMJR.";
return SBOX_ERROR_CREATE_APPCONTAINER_ACCESS_CHECK;
}
return SBOX_ALL_OK;
}
// static
bool SandboxWin::IsAppContainerEnabledForSandbox(
const base::CommandLine& command_line,
Sandbox sandbox_type) {
if (!sandbox::features::IsAppContainerSandboxSupported())
return false;
if (sandbox_type == Sandbox::kMediaFoundationCdm)
return true;
if (sandbox_type == Sandbox::kGpu)
return base::FeatureList::IsEnabled(features::kGpuAppContainer);
if (sandbox_type == Sandbox::kNetwork) {
return true;
}
if (sandbox_type == Sandbox::kOnDeviceModelExecution) {
return true;
}
#if BUILDFLAG(ENABLE_PRINTING)
if (sandbox_type == Sandbox::kPrintCompositor) {
return base::FeatureList::IsEnabled(
sandbox::policy::features::kPrintCompositorLPAC);
}
#endif
if (sandbox_type == Sandbox::kWindowsSystemProxyResolver)
return true;
return false;
}
class BrokerServicesDelegateImpl : public BrokerServicesDelegate {
public:
bool ParallelLaunchEnabled() override {
return features::IsParallelLaunchEnabled();
}
void ParallelLaunchPostTaskAndReplyWithResult(
const base::Location& from_here,
base::OnceCallback<CreateTargetResult()> task,
base::OnceCallback<void(CreateTargetResult)> reply) override {
base::ThreadPool::PostTaskAndReplyWithResult(
from_here,
{base::MayBlock(), base::TaskPriority::USER_BLOCKING,
base::TaskShutdownBehavior::BLOCK_SHUTDOWN},
std::move(task), std::move(reply));
}
void BeforeTargetProcessCreateOnCreationThread(
const void* trace_id) override {
int active_threads = ++creation_threads_in_use_;
base::UmaHistogramCounts100("MPArch.ChildProcessLaunchActivelyInParallel",
active_threads);
TRACE_EVENT_NESTABLE_ASYNC_BEGIN0("startup", "TargetProcess::Create",
trace_id);
}
void AfterTargetProcessCreateOnCreationThread(const void* trace_id,
DWORD process_id) override {
creation_threads_in_use_--;
TRACE_EVENT_NESTABLE_ASYNC_END1("startup", "TargetProcess::Create",
trace_id, "pid", process_id);
}
private:
// When parallel launching is enabled, target creation will happen on the
// thread pool. This is atomic to keep track of the number of threads that are
// currently creating processes.
std::atomic<int> creation_threads_in_use_ = 0;
};
// static
bool SandboxWin::InitBrokerServices(BrokerServices* broker_services) {
// TODO(abarth): DCHECK(CalledOnValidThread());
// See <http://b/1287166>.
DCHECK(broker_services);
DCHECK(!g_broker_services);
ResultCode init_result =
broker_services->Init(std::make_unique<BrokerServicesDelegateImpl>());
g_broker_services = broker_services;
// In non-official builds warn about dangerous uses of DuplicateHandle. This
// isn't useful under a component build, since there will be multiple modules,
// each of which may have a slot to patch (if the symbol is even present).
#if !defined(OFFICIAL_BUILD) && !defined(COMPONENT_BUILD)
BOOL is_in_job = FALSE;
CHECK(::IsProcessInJob(::GetCurrentProcess(), NULL, &is_in_job));
if (!is_in_job && !GetIATPatchFunctionHandle().is_patched()) {
HMODULE module = NULL;
wchar_t module_name[MAX_PATH];
CHECK(::GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
reinterpret_cast<LPCWSTR>(InitBrokerServices),
&module));
DWORD result = ::GetModuleFileNameW(module, module_name, MAX_PATH);
if (result && (result != MAX_PATH)) {
result = GetIATPatchFunctionHandle().Patch(
module_name, "kernel32.dll", "DuplicateHandle",
reinterpret_cast<void*>(DuplicateHandlePatch));
CHECK_EQ(0u, result);
g_iat_orig_duplicate_handle =
reinterpret_cast<DuplicateHandleFunctionPtr>(
GetIATPatchFunctionHandle().original_function());
}
}
#endif
return SBOX_ALL_OK == init_result;
}
// static
bool SandboxWin::InitTargetServices(TargetServices* target_services) {
DCHECK(target_services);
ResultCode result = target_services->Init();
return SBOX_ALL_OK == result;
}
// static
ResultCode SandboxWin::GeneratePolicyForSandboxedProcess(
const base::CommandLine& cmd_line,
const base::HandlesToInheritVector& handles_to_inherit,
SandboxDelegate* delegate,
TargetPolicy* policy) {
const base::CommandLine& launcher_process_command_line =
*base::CommandLine::ForCurrentProcess();
Sandbox sandbox_type = delegate->GetSandboxType();
// --no-sandbox and kNoSandbox are launched without a policy.
if (IsUnsandboxedProcess(sandbox_type, cmd_line,
launcher_process_command_line)) {
return ResultCode::SBOX_ERROR_UNSANDBOXED_PROCESS;
}
// Add any handles to be inherited to the policy.
for (HANDLE handle : handles_to_inherit)
policy->AddHandleToShare(handle);
if (!policy->GetConfig()->IsConfigured()) {
ResultCode result = GenerateConfigForSandboxedProcess(cmd_line, delegate,
policy->GetConfig());
if (result != SBOX_ALL_OK)
return result;
}
#if !defined(OFFICIAL_BUILD)
// If stdout/stderr point to a Windows console, these calls will
// have no effect. These calls can fail with SBOX_ERROR_BAD_PARAMS.
policy->SetStdoutHandle(GetStdHandle(STD_OUTPUT_HANDLE));
policy->SetStderrHandle(GetStdHandle(STD_ERROR_HANDLE));
#endif
if (!delegate->PreSpawnTarget(policy))
return SBOX_ERROR_DELEGATE_PRE_SPAWN;
return SBOX_ALL_OK;
}
// static
ResultCode SandboxWin::StartSandboxedProcess(
const base::CommandLine& cmd_line,
const base::HandlesToInheritVector& handles_to_inherit,
SandboxDelegate* delegate,
StartSandboxedProcessCallback result_callback) {
SandboxLaunchTimer timer;
// Avoid making a policy if we won't use it.
if (IsUnsandboxedProcess(delegate->GetSandboxType(), cmd_line,
*base::CommandLine::ForCurrentProcess())) {
base::Process process;
ResultCode result =
LaunchWithoutSandbox(cmd_line, handles_to_inherit, delegate, &process);
DWORD last_error = GetLastError();
std::move(result_callback).Run(std::move(process), last_error, result);
return SBOX_ALL_OK;
}
auto policy = g_broker_services->CreatePolicy(delegate->GetSandboxTag());
timer.OnPolicyCreated();
ResultCode result = GeneratePolicyForSandboxedProcess(
cmd_line, handles_to_inherit, delegate, policy.get());
if (SBOX_ALL_OK != result)
return result;
timer.OnPolicyGenerated();
int64_t trace_event_id = timer.GetStartTimeInMicroseconds();
TRACE_EVENT_NESTABLE_ASYNC_BEGIN0(
"startup", "StartProcessWithAccess::LAUNCHPROCESS", trace_event_id);
result = g_broker_services->SpawnTargetAsync(
cmd_line.GetProgram().value().c_str(),
cmd_line.GetCommandLineString().c_str(), std::move(policy),
base::BindOnce(&SandboxWin::FinishStartSandboxedProcess, delegate,
std::move(timer), std::move(result_callback)));
if (result != SBOX_ALL_OK) {
TRACE_EVENT_NESTABLE_ASYNC_END0(
"startup", "StartProcessWithAccess::LAUNCHPROCESS", trace_event_id);
if (result == SBOX_ERROR_GENERIC) {
DPLOG(ERROR) << "Failed to launch process";
} else {
DLOG(ERROR) << "Failed to launch process. Error: " << result;
}
}
return result;
}
// static
void SandboxWin::FinishStartSandboxedProcess(
SandboxDelegate* delegate,
SandboxLaunchTimer timer,
StartSandboxedProcessCallback result_callback,
base::win::ScopedProcessInformation target,
DWORD last_error,
ResultCode result) {
timer.OnProcessSpawned();
int64_t trace_event_id = timer.GetStartTimeInMicroseconds();
TRACE_EVENT_NESTABLE_ASYNC_END0(
"startup", "StartProcessWithAccess::LAUNCHPROCESS", trace_event_id);
if (SBOX_ALL_OK != result) {
base::UmaHistogramSparse("Process.Sandbox.Launch.Error", last_error);
if (result == SBOX_ERROR_GENERIC) {
DPLOG(ERROR) << "Failed to launch process";
} else {
DLOG(ERROR) << "Failed to launch process. Error: " << result;
}
std::move(result_callback).Run(base::Process(), last_error, result);
return;
}
delegate->PostSpawnTarget(target.process_handle());
CHECK(ResumeThread(target.thread_handle()) != static_cast<DWORD>(-1));
timer.OnProcessResumed();
// Record timing histogram on sandboxed & launched success.
if (SBOX_ALL_OK == result) {
timer.RecordHistograms();
}
base::Process process(target.TakeProcessHandle());
std::move(result_callback).Run(std::move(process), last_error, result);
}
// static
ResultCode SandboxWin::GetPolicyDiagnostics(
base::OnceCallback<void(base::Value)> response) {
CHECK(g_broker_services);
CHECK(!response.is_null());
auto receiver = std::make_unique<ServiceManagerDiagnosticsReceiver>(
base::SequencedTaskRunner::GetCurrentDefault(), std::move(response));
return g_broker_services->GetPolicyDiagnostics(std::move(receiver));
}
void BlocklistAddOneDllForTesting(const wchar_t* module_name,
TargetConfig* config) {
std::map<std::wstring, std::wstring> modules = GetShortNameModules();
BlocklistAddOneDll(module_name, modules, config);
}
// static
std::string SandboxWin::GetSandboxTypeInEnglish(Sandbox sandbox_type) {
switch (sandbox_type) {
case Sandbox::kNoSandbox:
return "Unsandboxed";
case Sandbox::kNoSandboxAndElevatedPrivileges:
return "Unsandboxed (Elevated)";
case Sandbox::kXrCompositing:
return "XR Compositing";
case Sandbox::kRenderer:
return "Renderer";
case Sandbox::kUtility:
return "Utility";
case Sandbox::kGpu:
return "GPU";
#if BUILDFLAG(ENABLE_PPAPI)
case Sandbox::kPpapi:
return "PPAPI";
#endif
case Sandbox::kNetwork:
return "Network";
case Sandbox::kOnDeviceModelExecution:
return "On-Device Model Execution";
case Sandbox::kCdm:
return "CDM";
case Sandbox::kPrintCompositor:
return "Print Compositor";
#if BUILDFLAG(ENABLE_OOP_PRINTING)
case Sandbox::kPrintBackend:
return "Print Backend";
#endif
case Sandbox::kAudio:
return "Audio";
#if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
case Sandbox::kScreenAI:
return "Screen AI";
#endif
case Sandbox::kSpeechRecognition:
return "Speech Recognition";
case Sandbox::kPdfConversion:
return "PDF Conversion";
case Sandbox::kMediaFoundationCdm:
return "Media Foundation CDM";
case Sandbox::kService:
return "Service";
case Sandbox::kServiceWithJit:
return "Service With Jit";
case Sandbox::kIconReader:
return "Icon Reader";
case Sandbox::kWindowsSystemProxyResolver:
return "Windows System Proxy Resolver";
}
}
// static
std::string SandboxWin::GetSandboxTagForDelegate(
std::string_view prefix,
sandbox::mojom::Sandbox sandbox_type) {
// sandbox.mojom.Sandbox has an operator << we can use for non-human values.
std::ostringstream stream;
stream << prefix << "!" << sandbox_type;
return stream.str();
}
// static
std::optional<size_t> SandboxWin::GetJobMemoryLimit(Sandbox sandbox_type) {
// Trigger feature list initialization here to ensure no population bias in
// the experimental and control groups.
[[maybe_unused]] const bool high_renderer_limits =
base::FeatureList::IsEnabled(
sandbox::policy::features::kWinSboxHighRendererJobMemoryLimits);
#if defined(ARCH_CPU_64_BITS)
size_t memory_limit = static_cast<size_t>(kDataSizeLimit);
if (sandbox_type == Sandbox::kGpu || sandbox_type == Sandbox::kRenderer ||
sandbox_type == Sandbox::kOnDeviceModelExecution) {
constexpr uint64_t GB = 1024 * 1024 * 1024;
// Allow the GPU/RENDERER process's sandbox to access more physical memory
// if it's available on the system.
//
// Renderer processes are allowed to access 16 GB; the GPU process, up
// to 64 GB.
uint64_t physical_memory = base::SysInfo::AmountOfPhysicalMemory();
if (sandbox_type == Sandbox::kGpu && physical_memory > 64 * GB) {
memory_limit = 64 * GB;
} else if (sandbox_type == Sandbox::kGpu && physical_memory > 32 * GB) {
memory_limit = 32 * GB;
} else if (physical_memory > 16 * GB) {
memory_limit = 16 * GB;
} else {
memory_limit = 8 * GB;
}
if (sandbox_type == Sandbox::kRenderer && high_renderer_limits) {
// Set limit to 1Tb.
memory_limit = 1024 * GB;
}
}
return memory_limit;
#else
return std::nullopt;
#endif
}
} // namespace policy
} // namespace sandbox
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