Fix race condition in checkPattern and verifyPattern. (9475460e) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/widget/LockPatternChecker.java

+19 −2

Original line number	Diff line number	Diff line
		@@ -4,6 +4,7 @@ import android.os.AsyncTask;

		import com.android.internal.widget.LockPatternUtils.RequestThrottledException;

		import java.util.ArrayList;
		import java.util.List;

		/**
		@@ -61,11 +62,19 @@ public final class LockPatternChecker {
		final OnVerifyCallback callback) {
		AsyncTask<Void, Void, byte[]> task = new AsyncTask<Void, Void, byte[]>() {
		private int mThrottleTimeout;
		private List<LockPatternView.Cell> patternCopy;

		@Override
		protected void onPreExecute() {
		// Make a copy of the pattern to prevent race conditions.
		// No need to clone the individual cells because they are immutable.
		patternCopy = new ArrayList(pattern);
		}

		@Override
		protected byte[] doInBackground(Void... args) {
		try {
		return utils.verifyPattern(pattern, challenge, userId);
		return utils.verifyPattern(patternCopy, challenge, userId);
		} catch (RequestThrottledException ex) {
		mThrottleTimeout = ex.getTimeoutMs();
		return null;
		@@ -95,11 +104,19 @@ public final class LockPatternChecker {
		final OnCheckCallback callback) {
		AsyncTask<Void, Void, Boolean> task = new AsyncTask<Void, Void, Boolean>() {
		private int mThrottleTimeout;
		private List<LockPatternView.Cell> patternCopy;

		@Override
		protected void onPreExecute() {
		// Make a copy of the pattern to prevent race conditions.
		// No need to clone the individual cells because they are immutable.
		patternCopy = new ArrayList(pattern);
		}

		@Override
		protected Boolean doInBackground(Void... args) {
		try {
		return utils.checkPattern(pattern, userId, callback::onEarlyMatched);
		return utils.checkPattern(patternCopy, userId, callback::onEarlyMatched);
		} catch (RequestThrottledException ex) {
		mThrottleTimeout = ex.getTimeoutMs();
		return false;