Add logic to keep track of COM callbacks and cancel them if the sessi…

src/windows/wslcsession/WSLCSession.cpp

@@ -21,6 +21,7 @@ Module Name:
 using namespace wsl::windows::common;
 using relay::MultiHandleWait;
 using wsl::shared::Localization;
+using wsl::windows::service::wslc::UserCOMCallback;
 using wsl::windows::service::wslc::UserHandle;
 using wsl::windows::service::wslc::WSLCSession;
 using wsl::windows::service::wslc::WSLCVirtualMachine;
@@ -220,6 +221,48 @@ HANDLE UserHandle::Get() const noexcept
     return m_handle;
 }
 
+UserCOMCallback::UserCOMCallback(WSLCSession& Session) : m_session(&Session), m_threadId(GetCurrentThreadId())
+{
+    THROW_IF_FAILED(CoEnableCallCancellation(nullptr));
+}
+
+UserCOMCallback::UserCOMCallback(UserCOMCallback&& Other)
+{
+    *this = std::move(Other);
+}
+
+UserCOMCallback& UserCOMCallback::operator=(UserCOMCallback&& Other)
+{
+    if (this != &Other)
+    {
+        Reset();
+        m_session = Other.m_session;
+        m_threadId = Other.m_threadId;
+
+        Other.m_threadId = 0;
+        Other.m_session = nullptr;
+    }
+    return *this;
+}
+
+void UserCOMCallback::Reset()
+{
+    if (m_threadId != 0)
+    {
+        WI_ASSERT(m_session != nullptr);
+
+        m_session->UnregisterUserCOMCallback(m_threadId);
+        m_threadId = 0;
+
+        THROW_IF_FAILED(CoDisableCallCancellation(nullptr));
+    }
+}
+
+UserCOMCallback::~UserCOMCallback()
+{
+    Reset();
+}
+
 HRESULT WSLCSession::GetProcessHandle(_Out_ HANDLE* ProcessHandle)
 try
 {
@@ -443,6 +486,12 @@ void WSLCSession::StreamImageOperation(DockerHTTPClient::HTTPRequestContext& req
         bool isJson = false;
     };
 
+    std::optional<UserCOMCallback> comCall;
+    if (ProgressCallback != nullptr)
+    {
+        comCall = RegisterUserCOMCallback();
+    }
+
     std::optional<Response> httpResponse;
 
     auto onHttpResponse = [&](const boost::beast::http::message<false, boost::beast::http::buffer_body>& response) {
@@ -589,6 +638,12 @@ try
 
     auto buildFileHandle = OpenUserHandle(Options->DockerfileHandle);
 
+    std::optional<UserCOMCallback> comCall;
+    if (ProgressCallback != nullptr)
+    {
+        comCall = RegisterUserCOMCallback();
+    }
+
     auto lock = m_lock.lock_shared();
 
     THROW_HR_IF(HRESULT_FROM_WIN32(ERROR_INVALID_STATE), !m_virtualMachine);
@@ -1918,6 +1973,14 @@ try
         CancelUserHandleIO();
     }
 
+    {
+        std::lock_guard comLock(m_userCOMCallbacksLock);
+
+        // Cancel any pending outgoing COM callback calls (e.g. IProgressCallback::OnProgress)
+        // to unblock operations waiting for cross-process COM responses.
+        CancelUserCOMCallbacks();
+    }
+
     // Acquire an exclusive lock to ensure that no operation is running.
     auto lock = m_lock.lock_exclusive();
     std::lock_guard containersLock(m_containersLock);
@@ -2154,6 +2217,38 @@ void WSLCSession::CancelUserHandleIO()
     }
 }
 
+UserCOMCallback WSLCSession::RegisterUserCOMCallback()
+{
+    std::lock_guard lock(m_userCOMCallbacksLock);
+
+    // Don't allow new COM calls if the session is terminating.
+    // N.B. This check must happen under m_userCOMCallbacksLock to synchronize with Terminate().
+    THROW_HR_IF_MSG(
+        E_ABORT, m_sessionTerminatingEvent.is_signaled(), "Refusing to make a COM callback while the session is terminating.");
+
+    m_userCOMCallbackThreads.emplace_back(GetCurrentThreadId());
+
+    return UserCOMCallback{*this};
+}
+
+void WSLCSession::UnregisterUserCOMCallback(DWORD ThreadId)
+{
+    std::lock_guard lock(m_userCOMCallbacksLock);
+
+    auto it = std::ranges::find(m_userCOMCallbackThreads, ThreadId);
+    WI_ASSERT(it != m_userCOMCallbackThreads.end());
+
+    m_userCOMCallbackThreads.erase(it);
+}
+
+void WSLCSession::CancelUserCOMCallbacks()
+{
+    for (auto threadId : m_userCOMCallbackThreads)
+    {
+        LOG_IF_FAILED(CoCancelCall(threadId, 0));
+    }
+}
+
 void WSLCSession::OnContainerDeleted(const WSLCContainerImpl* Container)
 {
     auto lock = m_lock.lock_shared();

src/windows/wslcsession/WSLCSession.h

@@ -48,6 +48,24 @@ class UserHandle
     HANDLE m_handle{};
 };
 
+class UserCOMCallback
+{
+    NON_COPYABLE(UserCOMCallback);
+
+public:
+    UserCOMCallback(WSLCSession& Session);
+    UserCOMCallback(UserCOMCallback&& Other);
+
+    ~UserCOMCallback();
+
+    UserCOMCallback& operator=(UserCOMCallback&& Other);
+    void Reset();
+
+private:
+    WSLCSession* m_session{};
+    DWORD m_threadId{};
+};
+
 //
 // WSLCSession - Implements IWSLCSession for container management.
 // Runs in a per-user COM server process for security isolation.
@@ -125,10 +143,14 @@ class DECLSPEC_UUID("4877FEFC-4977-4929-A958-9F36AA1892A4") WSLCSession
     UserHandle OpenUserHandle(WSLCHandle Handle);
     void ReleaseUserHandle(HANDLE Handle);
 
+    UserCOMCallback RegisterUserCOMCallback();
+    void UnregisterUserCOMCallback(DWORD ThreadId);
+
 private:
     ULONG m_id = 0;
 
     __requires_lock_held(m_userHandlesLock) void CancelUserHandleIO();
+    __requires_lock_held(m_userCOMCallbacksLock) void CancelUserCOMCallbacks();
     void ConfigureStorage(const WSLCSessionInitSettings& Settings, PSID UserSid);
     void Ext4Format(const std::string& Device);
     void OnContainerDeleted(const WSLCContainerImpl* Container);
@@ -169,6 +191,11 @@ class DECLSPEC_UUID("4877FEFC-4977-4929-A958-9F36AA1892A4") WSLCSession
     std::mutex m_userHandlesLock;
     __guarded_by(m_userHandlesLock) std::vector<HANDLE> m_userHandles;
 
+    // Threads currently inside an outgoing COM callback (e.g. IProgressCallback::OnProgress).
+    // Used by Terminate() to cancel stuck cross-process calls via CoCancelCall().
+    std::mutex m_userCOMCallbacksLock;
+    __guarded_by(m_userCOMCallbacksLock) std::vector<DWORD> m_userCOMCallbackThreads;
+
     // Used for testing only.
     std::mutex m_allocatedPortsLock;
     __guarded_by(m_allocatedPortsLock) std::map<uint16_t, std::pair<std::shared_ptr<VmPortAllocation>, size_t>> m_allocatedPorts;

test/windows/WSLCTests.cpp

@@ -2497,6 +2497,86 @@ class WSLCTests
         VERIFY_ARE_NOT_EQUAL(details, L"");
     }
 
+    WSLC_TEST_METHOD(BuildImageStuckCallbackCancellation)
+    {
+        class StuckBuildProgressCallback
+            : public Microsoft::WRL::RuntimeClass<Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::ClassicCom>, IProgressCallback>
+        {
+        public:
+            StuckBuildProgressCallback(std::promise<void>& reachedPromise, wil::unique_event& exitEvent) :
+                m_reachedPromise(reachedPromise), m_exitEvent(exitEvent)
+            {
+            }
+
+            HRESULT OnProgress(LPCSTR, LPCSTR, ULONGLONG, ULONGLONG) override
+            {
+                if (!m_signaled)
+                {
+                    m_signaled = true;
+                    m_reachedPromise.set_value();
+                    m_exitEvent.wait(); // Block until this test case is complete.
+                }
+
+                return S_OK;
+            }
+
+        private:
+            std::promise<void>& m_reachedPromise;
+            wil::unique_event& m_exitEvent;
+            bool m_signaled{};
+        };
+
+        auto contextDir = std::filesystem::current_path() / "build-context-stuck-callback";
+        std::filesystem::create_directories(contextDir);
+        auto cleanup = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, [&]() {
+            std::error_code ec;
+            std::filesystem::remove_all(contextDir, ec);
+        });
+
+        {
+            std::ofstream dockerfile(contextDir / "Dockerfile");
+            dockerfile << "FROM debian:latest\n";
+            dockerfile << "RUN echo hello\n";
+        }
+
+        auto contextPathStr = contextDir.wstring();
+        auto dockerfileHandle = wil::open_file((contextDir / "Dockerfile").c_str());
+
+        WSLCBuildImageOptions options{
+            .ContextPath = contextPathStr.c_str(),
+            .DockerfileHandle = ToCOMInputHandle(dockerfileHandle.get()),
+            .Flags = WSLCBuildImageFlagsVerbose,
+        };
+
+        std::promise<void> callbackReached;
+        wil::unique_event exitEvent{wil::EventOptions::ManualReset};
+        auto callback = Microsoft::WRL::Make<StuckBuildProgressCallback>(callbackReached, exitEvent);
+
+        std::promise<HRESULT> buildResult;
+        std::thread buildThread([&]() { buildResult.set_value(m_defaultSession->BuildImage(&options, callback.Get(), nullptr)); });
+
+        auto joinThread = wil::scope_exit([&]() {
+            exitEvent.SetEvent();
+            buildThread.join();
+        });
+
+        // Wait for the progress callback to be called, proving the COM call is in flight.
+        auto reachedFuture = callbackReached.get_future();
+        auto reachedStatus = reachedFuture.wait_for(std::chrono::seconds(60));
+        VERIFY_ARE_EQUAL(reachedStatus, std::future_status::ready);
+
+        // Terminate the session while the callback is stuck.
+        // This should cancel the pending COM call and unblock BuildImage.
+        VERIFY_SUCCEEDED(m_defaultSession->Terminate());
+
+        auto buildFuture = buildResult.get_future();
+        auto buildStatus = buildFuture.wait_for(std::chrono::seconds(30));
+        VERIFY_ARE_EQUAL(buildStatus, std::future_status::ready);
+
+        // BuildImage should have failed due to COM call cancellation.
+        VERIFY_FAILED(buildFuture.get());
+    }
+
     WSLC_TEST_METHOD(InteractiveShell)
     {
         WSLCProcessLauncher launcher("/bin/sh", {"/bin/sh"}, {"TERM=xterm-256color"}, WSLCProcessFlagsTty | WSLCProcessFlagsStdin);