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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
#include "mozilla/SandboxSettings.h"
#include "mozISandboxSettings.h"
#include "nsServiceManagerUtils.h"
#include "mozilla/Components.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_media.h"
#include "mozilla/StaticPrefs_network.h"
#include "mozilla/StaticPrefs_security.h"
#include "mozilla/StaticPrefs_webgl.h"
#include "prenv.h"
#ifdef XP_WIN
# include "mozilla/gfx/gfxVars.h"
# include "mozilla/WindowsVersion.h"
# include "nsAppRunner.h"
# include "nsExceptionHandler.h"
# include "PDMFactory.h"
#endif // XP_WIN
using namespace mozilla;
namespace mozilla {
const char* ContentWin32kLockdownStateToString(
nsIXULRuntime::ContentWin32kLockdownState aValue) {
switch (aValue) {
case nsIXULRuntime::ContentWin32kLockdownState::LockdownEnabled:
return "Win32k Lockdown enabled";
case nsIXULRuntime::ContentWin32kLockdownState::MissingWebRender:
return "Win32k Lockdown disabled -- Missing WebRender";
case nsIXULRuntime::ContentWin32kLockdownState::OperatingSystemNotSupported:
return "Win32k Lockdown disabled -- Operating system not supported";
case nsIXULRuntime::ContentWin32kLockdownState::PrefNotSet:
return "Win32k Lockdown disabled -- Preference not set";
case nsIXULRuntime::ContentWin32kLockdownState::MissingRemoteWebGL:
return "Win32k Lockdown disabled -- Missing Remote WebGL";
case nsIXULRuntime::ContentWin32kLockdownState::MissingNonNativeTheming:
return "Win32k Lockdown disabled -- Missing Non-Native Theming";
case nsIXULRuntime::ContentWin32kLockdownState::DecodersArentRemote:
return "Win32k Lockdown disabled -- Not all media decoders are remoted "
"to Utility Process";
case nsIXULRuntime::ContentWin32kLockdownState::DisabledByEnvVar:
return "Win32k Lockdown disabled -- MOZ_ENABLE_WIN32K is set";
case nsIXULRuntime::ContentWin32kLockdownState::DisabledBySafeMode:
return "Win32k Lockdown disabled -- Running in Safe Mode";
case nsIXULRuntime::ContentWin32kLockdownState::DisabledByE10S:
return "Win32k Lockdown disabled -- E10S is disabled";
case nsIXULRuntime::ContentWin32kLockdownState::DisabledByUserPref:
return "Win32k Lockdown disabled -- manually set "
"security.sandbox.content.win32k-disable to false";
case nsIXULRuntime::ContentWin32kLockdownState::EnabledByUserPref:
return "Win32k Lockdown enabled -- manually set "
"security.sandbox.content.win32k-disable to true";
case nsIXULRuntime::ContentWin32kLockdownState::DisabledByControlGroup:
return "Win32k Lockdown disabled -- user in Control Group";
case nsIXULRuntime::ContentWin32kLockdownState::EnabledByTreatmentGroup:
return "Win32k Lockdown enabled -- user in Treatment Group";
case nsIXULRuntime::ContentWin32kLockdownState::DisabledByDefault:
return "Win32k Lockdown disabled -- default value is false";
case nsIXULRuntime::ContentWin32kLockdownState::EnabledByDefault:
return "Win32k Lockdown enabled -- default value is true";
case nsIXULRuntime::ContentWin32kLockdownState::
IncompatibleMitigationPolicy:
return "Win32k Lockdown disabled -- Incompatible Windows Exploit "
"Protection policies enabled";
}
MOZ_CRASH("Should never reach here");
}
bool GetContentWin32kLockdownEnabled() {
auto state = GetContentWin32kLockdownState();
return state ==
nsIXULRuntime::ContentWin32kLockdownState::EnabledByUserPref ||
state == nsIXULRuntime::ContentWin32kLockdownState::
EnabledByTreatmentGroup ||
state == nsIXULRuntime::ContentWin32kLockdownState::EnabledByDefault;
}
nsIXULRuntime::ContentWin32kLockdownState GetContentWin32kLockdownState() {
#ifdef XP_WIN
static auto getLockdownState = [] {
auto state = GetWin32kLockdownState();
CrashReporter::RecordAnnotationCString(
CrashReporter::Annotation::ContentSandboxWin32kState,
ContentWin32kLockdownStateToString(state));
return state;
};
static nsIXULRuntime::ContentWin32kLockdownState result = getLockdownState();
return result;
#else // XP_WIN
return nsIXULRuntime::ContentWin32kLockdownState::OperatingSystemNotSupported;
#endif // XP_WIN
}
#if defined(XP_WIN)
static bool IsWebglOutOfProcessEnabled() {
if (StaticPrefs::webgl_out_of_process_force()) {
return true;
}
// We have to check initialization state for gfxVars, because of early use in
// child processes. In rare cases this could lead to the incorrect sandbox
// level being reported, but not the incorrect one being set.
if (gfx::gfxVars::IsInitialized() && !gfx::gfxVars::AllowWebglOop()) {
return false;
}
return StaticPrefs::webgl_out_of_process();
}
#endif
int GetEffectiveContentSandboxLevel() {
if (PR_GetEnv("MOZ_DISABLE_CONTENT_SANDBOX")) {
return 0;
}
int level = StaticPrefs::security_sandbox_content_level_DoNotUseDirectly();
// On Windows and macOS, enforce a minimum content sandbox level of 1 (except on
// Nightly, where it can be set to 0).
#if !defined(NIGHTLY_BUILD) && (defined(XP_WIN) || defined(XP_MACOSX))
if (level < 1) {
level = 1;
}
#endif
#ifdef XP_LINUX
// Level 1 was a configuration with default-deny seccomp-bpf but
// which allowed direct filesystem access; that required additional
// code for the syscall filter which was untested and tended to
// bit-rot. It was trivially escapable and was no longer being used
// even for debugging, so it has been removed.
//
// If the content sandbox is enabled, enforce a minimum level of 2.
static constexpr int kMinSupportedLevel = 2;
if (level > 0 && level <= kMinSupportedLevel) {
level = kMinSupportedLevel;
}
// Level 4 and up will break direct access to audio.
if (level > 3 && !StaticPrefs::media_cubeb_sandbox()) {
level = 3;
}
#endif
#if defined(XP_WIN)
// Sandbox level 8, which uses a USER_RESTRICTED access token level, breaks if
// prefs moving processing out of the content process are not the default.
// We are also disabling for safe mode initially.
if (level >= 8 &&
(gSafeMode || !IsWebglOutOfProcessEnabled() ||
!PDMFactory::AllDecodersAreRemote() ||
!StaticPrefs::network_process_enabled() ||
!Preferences::GetBool("media.peerconnection.mtransport_process"))) {
level = 7;
}
#endif
return level;
}
bool IsContentSandboxEnabled() { return GetEffectiveContentSandboxLevel() > 0; }
int GetEffectiveSocketProcessSandboxLevel() {
if (PR_GetEnv("MOZ_DISABLE_SOCKET_PROCESS_SANDBOX")) {
return 0;
}
int level =
StaticPrefs::security_sandbox_socket_process_level_DoNotUseDirectly();
return level;
}
int GetEffectiveGpuSandboxLevel() {
return StaticPrefs::security_sandbox_gpu_level();
}
#if defined(XP_MACOSX)
int ClampFlashSandboxLevel(const int aLevel) {
const int minLevel = 0;
const int maxLevel = 3;
if (aLevel < minLevel) {
return minLevel;
}
if (aLevel > maxLevel) {
return maxLevel;
}
return aLevel;
}
#endif
class SandboxSettings final : public mozISandboxSettings {
public:
NS_DECL_ISUPPORTS
NS_DECL_MOZISANDBOXSETTINGS
SandboxSettings() = default;
private:
~SandboxSettings() = default;
};
NS_IMPL_ISUPPORTS(SandboxSettings, mozISandboxSettings)
NS_IMETHODIMP SandboxSettings::GetEffectiveContentSandboxLevel(
int32_t* aRetVal) {
*aRetVal = mozilla::GetEffectiveContentSandboxLevel();
return NS_OK;
}
NS_IMETHODIMP SandboxSettings::GetContentWin32kLockdownState(int32_t* aRetVal) {
*aRetVal = static_cast<int32_t>(mozilla::GetContentWin32kLockdownState());
return NS_OK;
}
NS_IMETHODIMP
SandboxSettings::GetContentWin32kLockdownStateString(nsAString& aString) {
nsIXULRuntime::ContentWin32kLockdownState lockdownState =
mozilla::GetContentWin32kLockdownState();
aString = NS_ConvertASCIItoUTF16(
mozilla::ContentWin32kLockdownStateToString(lockdownState));
return NS_OK;
}
} // namespace mozilla
NS_IMPL_COMPONENT_FACTORY(mozISandboxSettings) {
return MakeAndAddRef<SandboxSettings>().downcast<nsISupports>();
}