Quelle ProcessRuntime.cpp Sprache: C

/* -*- 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, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/mscom/ProcessRuntime.h"

#include "mozilla/Assertions.h"
#include "mozilla/DynamicallyLinkedFunctionPtr.h"
#include "mozilla/mscom/COMWrappers.h"
#include "mozilla/mscom/ProcessRuntimeShared.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Unused.h"
#include "mozilla/Vector.h"
#include "mozilla/WindowsProcessMitigations.h"

#if defined(MOZILLA_INTERNAL_API)
#  include "mozilla/mscom/EnsureMTA.h"
#  if defined(MOZ_SANDBOX)
#    include "mozilla/sandboxTarget.h"
#  endif  // defined(MOZ_SANDBOX)
#endif    // defined(MOZILLA_INTERNAL_API)

#include <accctrl.h>
#include <aclapi.h>
#include <objbase.h>
#include <objidl.h>

// This API from oleaut32.dll is not declared in Windows SDK headers
extern "C" void __cdecl SetOaNoCache(void);

using namespace mozilla::mscom::detail;

namespace mozilla {
namespace mscom {

#if defined(MOZILLA_INTERNAL_API)
ProcessRuntime* ProcessRuntime::sInstance = nullptr;

ProcessRuntime::ProcessRuntime() : ProcessRuntime(XRE_GetProcessType()) {}

ProcessRuntime::ProcessRuntime(const GeckoProcessType aProcessType)
    : ProcessRuntime(aProcessType == GeckoProcessType_Default
                         ? ProcessCategory::GeckoBrowserParent
                         : ProcessCategory::GeckoChild) {}
#endif  // defined(MOZILLA_INTERNAL_API)

ProcessRuntime::ProcessRuntime(const ProcessCategory aProcessCategory)
    : mInitResult(CO_E_NOTINITIALIZED), mProcessCategory(aProcessCategory) {
#if defined(MOZILLA_INTERNAL_API)
  MOZ_DIAGNOSTIC_ASSERT(!sInstance);
  sInstance = this;

  EnsureMTA();
  /**
   * From this point forward, all threads in this process are implicitly
   * members of the multi-threaded apartment, with the following exceptions:
   * 1. If any Win32 GUI APIs were called on the current thread prior to
   *    executing this constructor, then this thread has already been implicitly
   *    initialized as the process's main STA thread; or
   * 2. A thread explicitly and successfully calls CoInitialize(Ex) to specify
   *    otherwise.
   */

  const bool isCurThreadImplicitMTA = IsCurrentThreadImplicitMTA();
  // We only assert that the implicit MTA precondition holds when not running
  // as the Gecko parent process.
  MOZ_DIAGNOSTIC_ASSERT(aProcessCategory ==
                            ProcessCategory::GeckoBrowserParent ||
                        isCurThreadImplicitMTA);

#  if defined(MOZ_SANDBOX)
  const bool isLockedDownChildProcess =
      mProcessCategory == ProcessCategory::GeckoChild && IsWin32kLockedDown();
  // If our process is running under Win32k lockdown, we cannot initialize
  // COM with a single-threaded apartment. This is because STAs create a hidden
  // window, which implicitly requires user32 and Win32k, which are blocked.
  // Instead we start the multi-threaded apartment and conduct our process-wide
  // COM initialization there.
  if (isLockedDownChildProcess) {
    // Make sure we're still running with the sandbox's privileged impersonation
    // token.
    HANDLE rawCurThreadImpToken;
    if (!::OpenThreadToken(::GetCurrentThread(), TOKEN_DUPLICATE | TOKEN_QUERY,
                           FALSE, &rawCurThreadImpToken)) {
      mInitResult = HRESULT_FROM_WIN32(::GetLastError());
      return;
    }
    nsAutoHandle curThreadImpToken(rawCurThreadImpToken);

    // Ensure that our current token is still an impersonation token (ie, we
    // have not yet called RevertToSelf() on this thread).
    DWORD len;
    TOKEN_TYPE tokenType;
    MOZ_RELEASE_ASSERT(
        ::GetTokenInformation(rawCurThreadImpToken, TokenType, &tokenType,
                              sizeof(tokenType), &len) &&
        len == sizeof(tokenType) && tokenType == TokenImpersonation);

    // Ideally we want our current thread to be running implicitly inside the
    // MTA, but if for some wacky reason we did not end up with that, we may
    // compensate by completing initialization via EnsureMTA's persistent
    // thread.
    if (!isCurThreadImplicitMTA) {
      InitUsingPersistentMTAThread(curThreadImpToken);
      return;
    }
  }
#  endif  // defined(MOZ_SANDBOX)
#endif    // defined(MOZILLA_INTERNAL_API)

  mAptRegion.Init(GetDesiredApartmentType(mProcessCategory));

  // It can happen that we are not the outermost COM initialization on this
  // thread. In fact it should regularly be the case that the outermost
  // initialization occurs from outside of XUL, before we show the skeleton UI,
  // at which point we still need to run some things here from within XUL.
  if (!mAptRegion.IsValidOutermost()) {
    mInitResult = mAptRegion.GetHResult();
#if defined(MOZILLA_INTERNAL_API)
    MOZ_ASSERT(mProcessCategory == ProcessCategory::GeckoBrowserParent);
    if (mProcessCategory != ProcessCategory::GeckoBrowserParent) {
      // This is unexpected unless we're GeckoBrowserParent
      return;
    }

    ProcessInitLock lock;

    // Is another instance of ProcessRuntime responsible for the outer
    // initialization?
    const bool prevInit =
        lock.GetInitState() == ProcessInitState::FullyInitialized;
    MOZ_ASSERT(prevInit);
    if (prevInit) {
      PostInit();
    }
#endif  // defined(MOZILLA_INTERNAL_API)
    return;
  }

  InitInsideApartment();
  if (FAILED(mInitResult)) {
    return;
  }

#if defined(MOZILLA_INTERNAL_API)
#  if defined(MOZ_SANDBOX)
  if (isLockedDownChildProcess) {
    // In locked-down child processes, defer PostInit until priv drop
    SandboxTarget::Instance()->RegisterSandboxStartCallback([self = this]() {
      // Ensure that we're still live and the init was successful before
      // calling PostInit()
      if (self == sInstance && SUCCEEDED(self->mInitResult)) {
        PostInit();
      }
    });
    return;
  }
#  endif  // defined(MOZ_SANDBOX)

  PostInit();
#endif  // defined(MOZILLA_INTERNAL_API)
}

#if defined(MOZILLA_INTERNAL_API)
ProcessRuntime::~ProcessRuntime() {
  MOZ_DIAGNOSTIC_ASSERT(sInstance == this);
  sInstance = nullptr;
}

#  if defined(MOZ_SANDBOX)
void ProcessRuntime::InitUsingPersistentMTAThread(
    const nsAutoHandle& aCurThreadToken) {
  // Create an impersonation token based on the current thread's token
  HANDLE rawMtaThreadImpToken = nullptr;
  if (!::DuplicateToken(aCurThreadToken, SecurityImpersonation,
                        &rawMtaThreadImpToken)) {
    mInitResult = HRESULT_FROM_WIN32(::GetLastError());
    return;
  }
  nsAutoHandle mtaThreadImpToken(rawMtaThreadImpToken);

  // Impersonate and initialize.
  bool tokenSet = false;
  EnsureMTA(
      [this, rawMtaThreadImpToken, &tokenSet]() -> void {
        if (!::SetThreadToken(nullptr, rawMtaThreadImpToken)) {
          mInitResult = HRESULT_FROM_WIN32(::GetLastError());
          return;
        }

        tokenSet = true;
        InitInsideApartment();
      },
      EnsureMTA::Option::ForceDispatchToPersistentThread);

  if (!tokenSet) {
    return;
  }

  SandboxTarget::Instance()->RegisterSandboxStartCallback(
      [self = this]() -> void {
        EnsureMTA(
            []() -> void {
              // This is a security risk if it fails, so we release assert
              MOZ_RELEASE_ASSERT(::RevertToSelf(),
                                 "mscom::ProcessRuntime RevertToSelf failed");
            },
            EnsureMTA::Option::ForceDispatchToPersistentThread);

        // Ensure that we're still live and the init was successful before
        // calling PostInit()
        if (self == sInstance && SUCCEEDED(self->mInitResult)) {
          PostInit();
        }
      });
}
#  endif  // defined(MOZ_SANDBOX)
#endif    // defined(MOZILLA_INTERNAL_API)

/* static */
COINIT ProcessRuntime::GetDesiredApartmentType(
    const ProcessRuntime::ProcessCategory aProcessCategory) {
  switch (aProcessCategory) {
    case ProcessCategory::GeckoBrowserParent:
      return COINIT_APARTMENTTHREADED;
    case ProcessCategory::GeckoChild:
      if (!IsWin32kLockedDown()) {
        // If Win32k is not locked down then we probably still need STA.
        // We disable DDE since that is not usable from child processes.
        return static_cast<COINIT>(COINIT_APARTMENTTHREADED |
                                   COINIT_DISABLE_OLE1DDE);
      }

      [[fallthrough]];
    default:
      return COINIT_MULTITHREADED;
  }
}

void ProcessRuntime::InitInsideApartment() {
  ProcessInitLock lock;
  const ProcessInitState prevInitState = lock.GetInitState();
  if (prevInitState == ProcessInitState::FullyInitialized) {
    // COM has already been initialized by a previous ProcessRuntime instance
    mInitResult = S_OK;
    return;
  }

  if (prevInitState < ProcessInitState::PartialSecurityInitialized) {
    // We are required to initialize security prior to configuring global
    // options.
    mInitResult = InitializeSecurity(mProcessCategory);
    // Downgrading from a MOZ_DIAGNOSTIC_ASSERT while investigating
    // bug 1930846.
    MOZ_ASSERT(SUCCEEDED(mInitResult));

    // Even though this isn't great, we should try to proceed even when
    // CoInitializeSecurity has previously been called: the additional settings
    // we want to change are important enough that we don't want to skip them.
    if (FAILED(mInitResult) && mInitResult != RPC_E_TOO_LATE) {
      return;
    }

    lock.SetInitState(ProcessInitState::PartialSecurityInitialized);
  }

  if (prevInitState < ProcessInitState::PartialGlobalOptions) {
    RefPtr<IGlobalOptions> globalOpts;
    mInitResult = wrapped::CoCreateInstance(
        CLSID_GlobalOptions, nullptr, CLSCTX_INPROC_SERVER, IID_IGlobalOptions,
        getter_AddRefs(globalOpts));
    MOZ_ASSERT(SUCCEEDED(mInitResult));
    if (FAILED(mInitResult)) {
      return;
    }

    // Disable COM's catch-all exception handler
    mInitResult = globalOpts->Set(COMGLB_EXCEPTION_HANDLING,
                                  COMGLB_EXCEPTION_DONOT_HANDLE_ANY);
    MOZ_ASSERT(SUCCEEDED(mInitResult));
    if (FAILED(mInitResult)) {
      return;
    }

    lock.SetInitState(ProcessInitState::PartialGlobalOptions);
  }

  // Disable the BSTR cache (as it never invalidates, thus leaking memory)
  // (This function is itself idempotent, so we do not concern ourselves with
  // tracking whether or not we've already called it.)
  ::SetOaNoCache();

  lock.SetInitState(ProcessInitState::FullyInitialized);
}

#if defined(MOZILLA_INTERNAL_API)
/**
* Guaranteed to run *after* the COM (and possible sandboxing) initialization
* has successfully completed and stabilized. This method MUST BE IDEMPOTENT!
*/
/* static */ void ProcessRuntime::PostInit() {
  // Currently "roughed-in" but unused.
}
#endif  // defined(MOZILLA_INTERNAL_API)

/* static */
DWORD
ProcessRuntime::GetClientThreadId() {
  DWORD callerTid;
  HRESULT hr = ::CoGetCallerTID(&callerTid);
  // Don't return callerTid unless the call succeeded and returned S_FALSE,
  // indicating that the caller originates from a different process.
  if (hr != S_FALSE) {
    return 0;
  }

  return callerTid;
}

/* static */
HRESULT
ProcessRuntime::InitializeSecurity(const ProcessCategory aProcessCategory) {
  HANDLE rawToken = nullptr;
  BOOL ok = ::OpenProcessToken(::GetCurrentProcess(), TOKEN_QUERY, &rawToken);
  if (!ok) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }
  nsAutoHandle token(rawToken);

  DWORD len = 0;
  ok = ::GetTokenInformation(token, TokenUser, nullptr, len, &len);
  DWORD win32Error = ::GetLastError();
  if (!ok && win32Error != ERROR_INSUFFICIENT_BUFFER) {
    HRESULT hr = HRESULT_FROM_WIN32(win32Error);
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  auto tokenUserBuf = MakeUnique<BYTE[]>(len);
  TOKEN_USER& tokenUser = *reinterpret_cast<TOKEN_USER*>(tokenUserBuf.get());
  ok = ::GetTokenInformation(token, TokenUser, tokenUserBuf.get(), len, &len);
  if (!ok) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  len = 0;
  ok = ::GetTokenInformation(token, TokenPrimaryGroup, nullptr, len, &len);
  win32Error = ::GetLastError();
  if (!ok && win32Error != ERROR_INSUFFICIENT_BUFFER) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  auto tokenPrimaryGroupBuf = MakeUnique<BYTE[]>(len);
  TOKEN_PRIMARY_GROUP& tokenPrimaryGroup =
      *reinterpret_cast<TOKEN_PRIMARY_GROUP*>(tokenPrimaryGroupBuf.get());
  ok = ::GetTokenInformation(token, TokenPrimaryGroup,
                             tokenPrimaryGroupBuf.get(), len, &len);
  if (!ok) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  SECURITY_DESCRIPTOR sd;
  if (!::InitializeSecurityDescriptor(&sd, SECURITY_DESCRIPTOR_REVISION)) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  BYTE systemSid[SECURITY_MAX_SID_SIZE];
  DWORD systemSidSize = sizeof(systemSid);
  if (!::CreateWellKnownSid(WinLocalSystemSid, nullptr, systemSid,
                            &systemSidSize)) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  BYTE adminSid[SECURITY_MAX_SID_SIZE];
  DWORD adminSidSize = sizeof(adminSid);
  if (!::CreateWellKnownSid(WinBuiltinAdministratorsSid, nullptr, adminSid,
                            &adminSidSize)) {
    HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  const bool allowAllNonRestrictedAppContainers =
      aProcessCategory == ProcessCategory::GeckoBrowserParent;

  BYTE appContainersSid[SECURITY_MAX_SID_SIZE];
  DWORD appContainersSidSize = sizeof(appContainersSid);
  if (allowAllNonRestrictedAppContainers) {
    if (!::CreateWellKnownSid(WinBuiltinAnyPackageSid, nullptr,
                              appContainersSid, &appContainersSidSize)) {
      HRESULT hr = HRESULT_FROM_WIN32(::GetLastError());
      MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
      return hr;
    }
  }

  UniquePtr<BYTE[]> tokenAppContainerInfBuf;
  len = 0;
  ::GetTokenInformation(token, TokenAppContainerSid, nullptr, len, &len);
  if (len) {
    tokenAppContainerInfBuf = MakeUnique<BYTE[]>(len);
    ok = ::GetTokenInformation(token, TokenAppContainerSid,
                               tokenAppContainerInfBuf.get(), len, &len);
    if (!ok) {
      // Don't fail if we get an error retrieving an app container SID.
      tokenAppContainerInfBuf = nullptr;
    }
  }

  // Grant access to SYSTEM, Administrators, the user, our app container (if in
  // one) and when running as the browser process on Windows 8+, all non
  // restricted app containers.
  const size_t kMaxInlineEntries = 5;
  mozilla::Vector<EXPLICIT_ACCESS_W, kMaxInlineEntries> entries;

  Unused << entries.append(EXPLICIT_ACCESS_W{
      COM_RIGHTS_EXECUTE,
      GRANT_ACCESS,
      NO_INHERITANCE,
      {nullptr, NO_MULTIPLE_TRUSTEE, TRUSTEE_IS_SID, TRUSTEE_IS_USER,
       reinterpret_cast<LPWSTR>(systemSid)}});

  Unused << entries.append(EXPLICIT_ACCESS_W{
      COM_RIGHTS_EXECUTE,
      GRANT_ACCESS,
      NO_INHERITANCE,
      {nullptr, NO_MULTIPLE_TRUSTEE, TRUSTEE_IS_SID,
       TRUSTEE_IS_WELL_KNOWN_GROUP, reinterpret_cast<LPWSTR>(adminSid)}});

  Unused << entries.append(EXPLICIT_ACCESS_W{
      COM_RIGHTS_EXECUTE,
      GRANT_ACCESS,
      NO_INHERITANCE,
      {nullptr, NO_MULTIPLE_TRUSTEE, TRUSTEE_IS_SID, TRUSTEE_IS_USER,
       reinterpret_cast<LPWSTR>(tokenUser.User.Sid)}});

  if (allowAllNonRestrictedAppContainers) {
    Unused << entries.append(
        EXPLICIT_ACCESS_W{COM_RIGHTS_EXECUTE,
                          GRANT_ACCESS,
                          NO_INHERITANCE,
                          {nullptr, NO_MULTIPLE_TRUSTEE, TRUSTEE_IS_SID,
                           TRUSTEE_IS_WELL_KNOWN_GROUP,
                           reinterpret_cast<LPWSTR>(appContainersSid)}});
  }

  if (tokenAppContainerInfBuf) {
    TOKEN_APPCONTAINER_INFORMATION& tokenAppContainerInf =
        *reinterpret_cast<TOKEN_APPCONTAINER_INFORMATION*>(
            tokenAppContainerInfBuf.get());

    // TokenAppContainer will be null if we are not in an app container.
    if (tokenAppContainerInf.TokenAppContainer) {
      Unused << entries.append(EXPLICIT_ACCESS_W{
          COM_RIGHTS_EXECUTE,
          GRANT_ACCESS,
          NO_INHERITANCE,
          {nullptr, NO_MULTIPLE_TRUSTEE, TRUSTEE_IS_SID, TRUSTEE_IS_USER,
           reinterpret_cast<LPWSTR>(tokenAppContainerInf.TokenAppContainer)}});
    }
  }

  PACL rawDacl = nullptr;
  win32Error =
      ::SetEntriesInAclW(entries.length(), entries.begin(), nullptr, &rawDacl);
  if (win32Error != ERROR_SUCCESS) {
    HRESULT hr = HRESULT_FROM_WIN32(win32Error);
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  UniquePtr<ACL, LocalFreeDeleter> dacl(rawDacl);

  if (!::SetSecurityDescriptorDacl(&sd, TRUE, dacl.get(), FALSE)) {
    HRESULT hr = HRESULT_FROM_WIN32(win32Error);
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  if (!::SetSecurityDescriptorOwner(&sd, tokenUser.User.Sid, FALSE)) {
    HRESULT hr = HRESULT_FROM_WIN32(win32Error);
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  if (!::SetSecurityDescriptorGroup(&sd, tokenPrimaryGroup.PrimaryGroup,
                                    FALSE)) {
    HRESULT hr = HRESULT_FROM_WIN32(win32Error);
    MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
    return hr;
  }

  HRESULT hr = wrapped::CoInitializeSecurity(
      &sd, -1, nullptr, nullptr, RPC_C_AUTHN_LEVEL_DEFAULT,
      RPC_C_IMP_LEVEL_IDENTIFY, nullptr, EOAC_NONE, nullptr);
  MOZ_DIAGNOSTIC_ASSERT(SUCCEEDED(hr));
  return hr;
}

}  // namespace mscom
}  // namespace mozilla

quality100%

¤ Dauer der Verarbeitung: 0.20 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.