Merge "Reland: Change input injection security model" (06517926) · Commits · e / os / android_frameworks_native

libs/input/android/os/InputEventInjectionResult.aidl

+2 −3

Original line number	Diff line number	Diff line
		@@ -29,9 +29,8 @@ enum InputEventInjectionResult {
		/* Injection succeeded. */
		SUCCEEDED = 0,

		/* Injection failed because the injector did not have permission to inject
		* into the application with input focus. */
		PERMISSION_DENIED = 1,
		/* Injection failed because the injected event did not target the appropriate window. */
		TARGET_MISMATCH = 1,

		/* Injection failed because there were no available input targets. */
		FAILED = 2,

services/inputflinger/benchmarks/InputDispatcher_benchmarks.cpp

+10 −12

Original line number	Diff line number	Diff line
		@@ -31,11 +31,11 @@ using android::os::InputEventInjectionSync;
		namespace android::inputdispatcher {

		// An arbitrary device id.
		static const int32_t DEVICE_ID = 1;
		constexpr int32_t DEVICE_ID = 1;

		// An arbitrary injector pid / uid pair that has permission to inject events.
		static const int32_t INJECTOR_PID = 999;
		static const int32_t INJECTOR_UID = 1001;
		// The default pid and uid for windows created by the test.
		constexpr int32_t WINDOW_PID = 999;
		constexpr int32_t WINDOW_UID = 1001;

		static constexpr std::chrono::duration INJECT_EVENT_TIMEOUT = 5s;
		static constexpr std::chrono::nanoseconds DISPATCHING_TIMEOUT = 100ms;
		@@ -106,8 +106,6 @@ private:

		void pokeUserActivity(nsecs_t, int32_t, int32_t) override {}

		bool checkInjectEventsPermissionNonReentrant(int32_t, int32_t) override { return false; }

		void onPointerDownOutsideFocus(const sp<IBinder>& newToken) override {}

		void setPointerCapture(const PointerCaptureRequest&) override {}
		@@ -194,8 +192,8 @@ public:
		mInfo.globalScaleFactor = 1.0;
		mInfo.touchableRegion.clear();
		mInfo.addTouchableRegion(mFrame);
		mInfo.ownerPid = INJECTOR_PID;
		mInfo.ownerUid = INJECTOR_UID;
		mInfo.ownerPid = WINDOW_PID;
		mInfo.ownerUid = WINDOW_UID;
		mInfo.displayId = ADISPLAY_ID_DEFAULT;
		}

		@@ -308,14 +306,14 @@ static void benchmarkInjectMotion(benchmark::State& state) {
		for (auto _ : state) {
		MotionEvent event = generateMotionEvent();
		// Send ACTION_DOWN
		dispatcher.injectInputEvent(&event, INJECTOR_PID, INJECTOR_UID,
		InputEventInjectionSync::NONE, INJECT_EVENT_TIMEOUT,
		dispatcher.injectInputEvent(&event, {} /targetUid/, InputEventInjectionSync::NONE,
		INJECT_EVENT_TIMEOUT,
		POLICY_FLAG_FILTERED \| POLICY_FLAG_PASS_TO_USER);

		// Send ACTION_UP
		event.setAction(AMOTION_EVENT_ACTION_UP);
		dispatcher.injectInputEvent(&event, INJECTOR_PID, INJECTOR_UID,
		InputEventInjectionSync::NONE, INJECT_EVENT_TIMEOUT,
		dispatcher.injectInputEvent(&event, {} /targetUid/, InputEventInjectionSync::NONE,
		INJECT_EVENT_TIMEOUT,
		POLICY_FLAG_FILTERED \| POLICY_FLAG_PASS_TO_USER);

		window->consumeEvent();

services/inputflinger/dispatcher/InjectionState.cpp

+2 −3

Original line number	Diff line number	Diff line
		@@ -20,10 +20,9 @@

		namespace android::inputdispatcher {

		InjectionState::InjectionState(int32_t injectorPid, int32_t injectorUid)
		InjectionState::InjectionState(const std::optional<int32_t>& targetUid)
		: refCount(1),
		injectorPid(injectorPid),
		injectorUid(injectorUid),
		targetUid(targetUid),
		injectionResult(android::os::InputEventInjectionResult::PENDING),
		injectionIsAsync(false),
		pendingForegroundDispatches(0) {}

services/inputflinger/dispatcher/InjectionState.h

+2 −3

Original line number	Diff line number	Diff line
		@@ -27,13 +27,12 @@ namespace inputdispatcher {
		struct InjectionState {
		mutable int32_t refCount;

		int32_t injectorPid;
		int32_t injectorUid;
		std::optional<int32_t> targetUid;
		android::os::InputEventInjectionResult injectionResult; // initially PENDING
		bool injectionIsAsync; // set to true if injection is not waiting for the result
		int32_t pendingForegroundDispatches; // the number of foreground dispatches in progress

		InjectionState(int32_t injectorPid, int32_t injectorUid);
		explicit InjectionState(const std::optional<int32_t>& targetUid);
		void release();

		private:

services/inputflinger/dispatcher/InputDispatcher.cpp

+87 −81

Original line number	Diff line number	Diff line
		@@ -577,6 +577,27 @@ bool isWindowOwnedBy(const sp<WindowInfoHandle>& windowHandle, int32_t pid, int3
		return false;
		}

		// Checks targeted injection using the window's owner's uid.
		// Returns an empty string if an entry can be sent to the given window, or an error message if the
		// entry is a targeted injection whose uid target doesn't match the window owner.
		std::optional<std::string> verifyTargetedInjection(const sp<WindowInfoHandle>& window,
		const EventEntry& entry) {
		if (entry.injectionState == nullptr \|\| !entry.injectionState->targetUid) {
		// The event was not injected, or the injected event does not target a window.
		return {};
		}
		const int32_t uid = *entry.injectionState->targetUid;
		if (window == nullptr) {
		return StringPrintf("No valid window target for injection into uid %d.", uid);
		}
		if (entry.injectionState->targetUid != window->getInfo()->ownerUid) {
		return StringPrintf("Injected event targeted at uid %d would be dispatched to window '%s' "
		"owned by uid %d.",
		uid, window->getName().c_str(), window->getInfo()->ownerUid);
		}
		return {};
		}

		} // namespace

		// --- InputDispatcher ---
		@@ -1035,6 +1056,8 @@ bool InputDispatcher::enqueueInboundEventLocked(std::unique_ptr<EventEntry> newE

		switch (entry.type) {
		case EventEntry::Type::KEY: {
		LOG_ALWAYS_FATAL_IF((entry.policyFlags & POLICY_FLAG_TRUSTED) == 0,
		"Unexpected untrusted event.");
		// Optimize app switch latency.
		// If the application takes too long to catch up then we drop all events preceding
		// the app switch key.
		@@ -1072,6 +1095,8 @@ bool InputDispatcher::enqueueInboundEventLocked(std::unique_ptr<EventEntry> newE
		}

		case EventEntry::Type::MOTION: {
		LOG_ALWAYS_FATAL_IF((entry.policyFlags & POLICY_FLAG_TRUSTED) == 0,
		"Unexpected untrusted event.");
		if (shouldPruneInboundQueueLocked(static_cast<MotionEntry&>(entry))) {
		mNextUnblockedEvent = mInboundQueue.back();
		needWake = true;
		@@ -1719,8 +1744,7 @@ bool InputDispatcher::dispatchMotionLocked(nsecs_t currentTime, std::shared_ptr<
		}

		setInjectionResult(*entry, injectionResult);
		if (injectionResult == InputEventInjectionResult::PERMISSION_DENIED) {
		ALOGW("Permission denied, dropping the motion (isPointer=%s)", toString(isPointerEvent));
		if (injectionResult == InputEventInjectionResult::TARGET_MISMATCH) {
		return true;
		}
		if (injectionResult != InputEventInjectionResult::SUCCEEDED) {
		@@ -1977,9 +2001,10 @@ InputEventInjectionResult InputDispatcher::findFocusedWindowTargetsLocked(
		// we have a valid, non-null focused window
		resetNoFocusedWindowTimeoutLocked();

		// Check permissions.
		if (!checkInjectionPermission(focusedWindowHandle, entry.injectionState)) {
		return InputEventInjectionResult::PERMISSION_DENIED;
		// Verify targeted injection.
		if (const auto err = verifyTargetedInjection(focusedWindowHandle, entry); err) {
		ALOGW("Dropping injected event: %s", (*err).c_str());
		return InputEventInjectionResult::TARGET_MISMATCH;
		}

		if (focusedWindowHandle->getInfo()->inputConfig.test(
		@@ -2045,11 +2070,6 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		nsecs_t currentTime, const MotionEntry& entry, std::vector<InputTarget>& inputTargets,
		nsecs_t* nextWakeupTime, bool* outConflictingPointerActions) {
		ATRACE_CALL();
		enum InjectionPermission {
		INJECTION_PERMISSION_UNKNOWN,
		INJECTION_PERMISSION_GRANTED,
		INJECTION_PERMISSION_DENIED
		};

		// For security reasons, we defer updating the touch state until we are sure that
		// event injection will be allowed.
		@@ -2059,7 +2079,6 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(

		// Update the touch state as needed based on the properties of the touch event.
		InputEventInjectionResult injectionResult = InputEventInjectionResult::PENDING;
		InjectionPermission injectionPermission = INJECTION_PERMISSION_UNKNOWN;
		sp<WindowInfoHandle> newHoverWindowHandle(mLastHoverWindowHandle);
		sp<WindowInfoHandle> newTouchedWindowHandle;

		@@ -2108,7 +2127,7 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		"in display %" PRId32,
		displayId);
		// TODO: test multiple simultaneous input streams.
		injectionResult = InputEventInjectionResult::PERMISSION_DENIED;
		injectionResult = InputEventInjectionResult::FAILED;
		switchedDevice = false;
		wrongDevice = true;
		goto Failed;
		@@ -2141,6 +2160,14 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		newTouchedWindowHandle = tempTouchState.getFirstForegroundWindowHandle();
		}

		// Verify targeted injection.
		if (const auto err = verifyTargetedInjection(newTouchedWindowHandle, entry); err) {
		ALOGW("Dropping injected touch event: %s", (*err).c_str());
		injectionResult = os::InputEventInjectionResult::TARGET_MISMATCH;
		newTouchedWindowHandle = nullptr;
		goto Failed;
		}

		// Figure out whether splitting will be allowed for this window.
		if (newTouchedWindowHandle != nullptr) {
		if (newTouchedWindowHandle->getInfo()->supportsSplitTouch()) {
		@@ -2184,6 +2211,11 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		for (const sp<WindowInfoHandle>& windowHandle : newTouchedWindows) {
		const WindowInfo& info = *windowHandle->getInfo();

		// Skip spy window targets that are not valid for targeted injection.
		if (const auto err = verifyTargetedInjection(windowHandle, entry); err) {
		continue;
		}

		if (info.inputConfig.test(WindowInfo::InputConfig::PAUSE_DISPATCHING)) {
		ALOGI("Not sending touch event to %s because it is paused",
		windowHandle->getName().c_str());
		@@ -2271,6 +2303,14 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		newTouchedWindowHandle =
		findTouchedWindowAtLocked(displayId, x, y, &tempTouchState, isStylus);

		// Verify targeted injection.
		if (const auto err = verifyTargetedInjection(newTouchedWindowHandle, entry); err) {
		ALOGW("Dropping injected event: %s", (*err).c_str());
		injectionResult = os::InputEventInjectionResult::TARGET_MISMATCH;
		newTouchedWindowHandle = nullptr;
		goto Failed;
		}

		// Drop touch events if requested by input feature
		if (newTouchedWindowHandle != nullptr &&
		shouldDropInput(entry, newTouchedWindowHandle)) {
		@@ -2362,19 +2402,26 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		goto Failed;
		}

		// Check permission to inject into all touched foreground windows.
		if (std::any_of(tempTouchState.windows.begin(), tempTouchState.windows.end(),
		[this, &entry](const TouchedWindow& touchedWindow) {
		return (touchedWindow.targetFlags & InputTarget::FLAG_FOREGROUND) != 0 &&
		!checkInjectionPermission(touchedWindow.windowHandle,
		entry.injectionState);
		})) {
		injectionResult = InputEventInjectionResult::PERMISSION_DENIED;
		injectionPermission = INJECTION_PERMISSION_DENIED;
		// Ensure that all touched windows are valid for injection.
		if (entry.injectionState != nullptr) {
		std::string errs;
		for (const TouchedWindow& touchedWindow : tempTouchState.windows) {
		if (touchedWindow.targetFlags & InputTarget::FLAG_DISPATCH_AS_OUTSIDE) {
		// Allow ACTION_OUTSIDE events generated by targeted injection to be
		// dispatched to any uid, since the coords will be zeroed out later.
		continue;
		}
		const auto err = verifyTargetedInjection(touchedWindow.windowHandle, entry);
		if (err) errs += "\n - " + *err;
		}
		if (!errs.empty()) {
		ALOGW("Dropping targeted injection: At least one touched window is not owned by uid "
		"%d:%s",
		*entry.injectionState->targetUid, errs.c_str());
		injectionResult = InputEventInjectionResult::TARGET_MISMATCH;
		goto Failed;
		}
		// Permission granted to inject into all touched foreground windows.
		injectionPermission = INJECTION_PERMISSION_GRANTED;
		}

		// Check whether windows listening for outside touches are owned by the same UID. If it is
		// set the policy flag that we will not reveal coordinate information to this window.
		@@ -2440,19 +2487,6 @@ InputEventInjectionResult InputDispatcher::findTouchedWindowTargetsLocked(
		tempTouchState.filterNonAsIsTouchWindows();

		Failed:
		// Check injection permission once and for all.
		if (injectionPermission == INJECTION_PERMISSION_UNKNOWN) {
		if (checkInjectionPermission(nullptr, entry.injectionState)) {
		injectionPermission = INJECTION_PERMISSION_GRANTED;
		} else {
		injectionPermission = INJECTION_PERMISSION_DENIED;
		}
		}

		if (injectionPermission != INJECTION_PERMISSION_GRANTED) {
		return injectionResult;
		}

		// Update final pieces of touch state if the injector had permission.
		if (!wrongDevice) {
		if (switchedDevice) {
		@@ -2650,26 +2684,6 @@ void InputDispatcher::addGlobalMonitoringTargetsLocked(std::vector<InputTarget>&
		}
		}

		bool InputDispatcher::checkInjectionPermission(const sp<WindowInfoHandle>& windowHandle,
		const InjectionState* injectionState) {
		if (injectionState &&
		(windowHandle == nullptr \|\|
		windowHandle->getInfo()->ownerUid != injectionState->injectorUid) &&
		!hasInjectionPermission(injectionState->injectorPid, injectionState->injectorUid)) {
		if (windowHandle != nullptr) {
		ALOGW("Permission denied: injecting event from pid %d uid %d to window %s "
		"owned by uid %d",
		injectionState->injectorPid, injectionState->injectorUid,
		windowHandle->getName().c_str(), windowHandle->getInfo()->ownerUid);
		} else {
		ALOGW("Permission denied: injecting event from pid %d uid %d",
		injectionState->injectorPid, injectionState->injectorUid);
		}
		return false;
		}
		return true;
		}

		/**
		* Indicate whether one window handle should be considered as obscuring
		* another window handle. We only check a few preconditions. Actually
		@@ -4188,20 +4202,20 @@ void InputDispatcher::notifyPointerCaptureChanged(const NotifyPointerCaptureChan
		}
		}

		InputEventInjectionResult InputDispatcher::injectInputEvent(
		const InputEvent* event, int32_t injectorPid, int32_t injectorUid,
		InputEventInjectionSync syncMode, std::chrono::milliseconds timeout, uint32_t policyFlags) {
		InputEventInjectionResult InputDispatcher::injectInputEvent(const InputEvent* event,
		std::optional<int32_t> targetUid,
		InputEventInjectionSync syncMode,
		std::chrono::milliseconds timeout,
		uint32_t policyFlags) {
		if (DEBUG_INBOUND_EVENT_DETAILS) {
		ALOGD("injectInputEvent - eventType=%d, injectorPid=%d, injectorUid=%d, "
		"syncMode=%d, timeout=%lld, policyFlags=0x%08x",
		event->getType(), injectorPid, injectorUid, syncMode, timeout.count(), policyFlags);
		ALOGD("injectInputEvent - eventType=%d, targetUid=%s, syncMode=%d, timeout=%lld, "
		"policyFlags=0x%08x",
		event->getType(), targetUid ? std::to_string(*targetUid).c_str() : "none", syncMode,
		timeout.count(), policyFlags);
		}
		nsecs_t endTime = now() + std::chrono::duration_cast<std::chrono::nanoseconds>(timeout).count();

		policyFlags \|= POLICY_FLAG_INJECTED;
		if (hasInjectionPermission(injectorPid, injectorUid)) {
		policyFlags \|= POLICY_FLAG_TRUSTED;
		}
		policyFlags \|= POLICY_FLAG_INJECTED \| POLICY_FLAG_TRUSTED;

		// For all injected events, set device id = VIRTUAL_KEYBOARD_ID. The only exception is events
		// that have gone through the InputFilter. If the event passed through the InputFilter, assign
		@@ -4342,7 +4356,7 @@ InputEventInjectionResult InputDispatcher::injectInputEvent(
		return InputEventInjectionResult::FAILED;
		}

		InjectionState* injectionState = new InjectionState(injectorPid, injectorUid);
		InjectionState* injectionState = new InjectionState(targetUid);
		if (syncMode == InputEventInjectionSync::NONE) {
		injectionState->injectionIsAsync = true;
		}
		@@ -4414,8 +4428,7 @@ InputEventInjectionResult InputDispatcher::injectInputEvent(
		} // release lock

		if (DEBUG_INJECTION) {
		ALOGD("injectInputEvent - Finished with result %d. injectorPid=%d, injectorUid=%d",
		injectionResult, injectorPid, injectorUid);
		ALOGD("injectInputEvent - Finished with result %d.", injectionResult);
		}

		return injectionResult;
		@@ -4454,19 +4467,12 @@ std::unique_ptr<VerifiedInputEvent> InputDispatcher::verifyInputEvent(const Inpu
		return result;
		}

		bool InputDispatcher::hasInjectionPermission(int32_t injectorPid, int32_t injectorUid) {
		return injectorUid == 0 \|\|
		mPolicy->checkInjectEventsPermissionNonReentrant(injectorPid, injectorUid);
		}

		void InputDispatcher::setInjectionResult(EventEntry& entry,
		InputEventInjectionResult injectionResult) {
		InjectionState* injectionState = entry.injectionState;
		if (injectionState) {
		if (DEBUG_INJECTION) {
		ALOGD("Setting input event injection result to %d. "
		"injectorPid=%d, injectorUid=%d",
		injectionResult, injectionState->injectorPid, injectionState->injectorUid);
		ALOGD("Setting input event injection result to %d.", injectionResult);
		}

		if (injectionState->injectionIsAsync && !(entry.policyFlags & POLICY_FLAG_FILTERED)) {
		@@ -4475,12 +4481,12 @@ void InputDispatcher::setInjectionResult(EventEntry& entry,
		case InputEventInjectionResult::SUCCEEDED:
		ALOGV("Asynchronous input event injection succeeded.");
		break;
		case InputEventInjectionResult::TARGET_MISMATCH:
		ALOGV("Asynchronous input event injection target mismatch.");
		break;
		case InputEventInjectionResult::FAILED:
		ALOGW("Asynchronous input event injection failed.");
		break;
		case InputEventInjectionResult::PERMISSION_DENIED:
		ALOGW("Asynchronous input event injection permission denied.");
		break;
		case InputEventInjectionResult::TIMED_OUT:
		ALOGW("Asynchronous input event injection timed out.");
		break;