Rejigger the invalid-key checks at backup time (cba5941c) · Commits · e / os / android_frameworks_base

core/java/android/app/IBackupAgent.aidl

+8 −0

Original line number	Diff line number	Diff line
		@@ -124,4 +124,12 @@ oneway interface IBackupAgent {
		int type, String domain, String path, long mode, long mtime,
		int token, IBackupManager callbackBinder);

		/**
		* Out of band: instruct the agent to crash within the client process. This is used
		* when the backup infrastructure detects a semantic error post-hoc and needs to
		* pass the problem back to the app.
		*
		* @param message The message to be passed to the agent's application in an exception.
		*/
		void fail(String message);
		}

core/java/android/app/backup/BackupAgent.java

+27 −5

Original line number	Diff line number	Diff line
		@@ -128,6 +128,13 @@ public abstract class BackupAgent extends ContextWrapper {

		Handler mHandler = null;

		Handler getHandler() {
		if (mHandler == null) {
		mHandler = new Handler(Looper.getMainLooper());
		}
		return mHandler;
		}

		class SharedPrefsSynchronizer implements Runnable {
		public final CountDownLatch mLatch = new CountDownLatch(1);

		@@ -140,12 +147,9 @@ public abstract class BackupAgent extends ContextWrapper {

		// Syncing shared preferences deferred writes needs to happen on the main looper thread
		private void waitForSharedPrefs() {
		if (mHandler == null) {
		mHandler = new Handler(Looper.getMainLooper());
		}

		Handler h = getHandler();
		final SharedPrefsSynchronizer s = new SharedPrefsSynchronizer();
		mHandler.postAtFrontOfQueue(s);
		h.postAtFrontOfQueue(s);
		try {
		s.mLatch.await();
		} catch (InterruptedException e) { /* ignored */ }
		@@ -680,5 +684,23 @@ public abstract class BackupAgent extends ContextWrapper {
		}
		}
		}

		@Override
		public void fail(String message) {
		getHandler().post(new FailRunnable(message));
		}
		}

		static class FailRunnable implements Runnable {
		private String mMessage;

		FailRunnable(String message) {
		mMessage = message;
		}

		@Override
		public void run() {
		throw new IllegalStateException(mMessage);
		}
		}
		}

core/java/android/app/backup/BackupDataOutput.java

+0 −5

Original line number	Diff line number	Diff line
		@@ -85,11 +85,6 @@ public class BackupDataOutput {
		* @throws IOException if the write failed
		*/
		public int writeEntityHeader(String key, int dataSize) throws IOException {
		if (key != null && key.charAt(0) >= 0xff00) {
		if (Process.myUid() != Process.SYSTEM_UID) {
		throw new IllegalArgumentException("Invalid key " + key);
		}
		}
		int result = writeEntityHeader_native(mBackupWriter, key, dataSize);
		if (result >= 0) {
		return result;

services/backup/java/com/android/server/backup/BackupManagerService.java

+46 −4

Original line number	Diff line number	Diff line
		@@ -2035,6 +2035,7 @@ public class BackupManagerService extends IBackupManager.Stub {
		BackupState mCurrentState;

		// carried information about the current in-flight operation
		IBackupAgent mAgentBinder;
		PackageInfo mCurrentPackage;
		File mSavedStateName;
		File mBackupDataName;
		@@ -2097,6 +2098,7 @@ public class BackupManagerService extends IBackupManager.Stub {
		addBackupTrace(b.toString());
		}

		mAgentBinder = null;
		mStatus = BackupConstants.TRANSPORT_OK;

		// Sanity check: if the queue is empty we have no work to do.
		@@ -2228,6 +2230,7 @@ public class BackupManagerService extends IBackupManager.Stub {
		IApplicationThread.BACKUP_MODE_INCREMENTAL);
		addBackupTrace("agent bound; a? = " + (agent != null));
		if (agent != null) {
		mAgentBinder = agent;
		mStatus = invokeAgentForBackup(request.packageName, agent, mTransport);
		// at this point we'll either get a completion callback from the
		// agent, or a timeout message on the main handler. either way, we're
		@@ -2253,6 +2256,7 @@ public class BackupManagerService extends IBackupManager.Stub {
		// That means we need to direct to the next state ourselves.
		if (mStatus != BackupConstants.TRANSPORT_OK) {
		BackupState nextState = BackupState.RUNNING_QUEUE;
		mAgentBinder = null;

		// An agent-level failure means we reenqueue this one agent for
		// a later retry, but otherwise proceed normally.
		@@ -2274,6 +2278,7 @@ public class BackupManagerService extends IBackupManager.Stub {

		executeNextState(nextState);
		} else {
		// success case
		addBackupTrace("expecting completion/timeout callback");
		}
		}
		@@ -2402,14 +2407,52 @@ public class BackupManagerService extends IBackupManager.Stub {
		return BackupConstants.TRANSPORT_OK;
		}

		public void failAgent(IBackupAgent agent, String message) {
		try {
		agent.fail(message);
		} catch (Exception e) {
		Slog.w(TAG, "Error conveying failure to " + mCurrentPackage.packageName);
		}
		}

		@Override
		public void operationComplete() {
		// Okay, the agent successfully reported back to us. The next thing we do is
		// push the app widget state for the app, if any.
		// Okay, the agent successfully reported back to us!
		final String pkgName = mCurrentPackage.packageName;
		final long filepos = mBackupDataName.length();
		FileDescriptor fd = mBackupData.getFileDescriptor();
		try {
		// If it's a 3rd party app, see whether they wrote any protected keys
		// and complain mightily if they are attempting shenanigans.
		if (mCurrentPackage.applicationInfo != null &&
		(mCurrentPackage.applicationInfo.flags&ApplicationInfo.FLAG_SYSTEM) == 0) {
		ParcelFileDescriptor readFd = ParcelFileDescriptor.open(mBackupDataName,
		ParcelFileDescriptor.MODE_READ_ONLY);
		BackupDataInput in = new BackupDataInput(readFd.getFileDescriptor());
		try {
		while (in.readNextHeader()) {
		final String key = in.getKey();
		if (key != null && key.charAt(0) >= 0xff00) {
		// Not okay: crash them and bail.
		failAgent(mAgentBinder, "Illegal backup key: " + key);
		addBackupTrace("illegal key " + key + " from " + pkgName);
		EventLog.writeEvent(EventLogTags.BACKUP_AGENT_FAILURE, pkgName,
		"bad key");
		mBackupHandler.removeMessages(MSG_TIMEOUT);
		agentErrorCleanup();
		// agentErrorCleanup() implicitly executes next state properly
		return;
		}
		in.skipEntityData();
		}
		} finally {
		if (readFd != null) {
		readFd.close();
		}
		}
		}

		// Piggyback the widget state payload, if any
		BackupDataOutput out = new BackupDataOutput(fd);
		byte[] widgetState = AppWidgetBackupBridge.getWidgetState(pkgName,
		UserHandle.USER_OWNER);
		@@ -2434,8 +2477,7 @@ public class BackupManagerService extends IBackupManager.Stub {
		}
		}

		// Spin the data off to the
		// transport and proceed with the next stage.
		// Spin the data off to the transport and proceed with the next stage.
		if (MORE_DEBUG) Slog.v(TAG, "operationComplete(): sending data to transport for "
		+ pkgName);
		mBackupHandler.removeMessages(MSG_TIMEOUT);