Fix NPE during fingerprint removal

1) Enroll fingerprint
2) Remove lockscreen credential
3) All fingerprints removed successfully

Bug: 180689674
Test: See steps above
Change-Id: I8ae947114ec1cc90738152ec33c13cc62c302559

1 files changed, 41 insertions, 11 deletions

diff --git a/core/java/android/hardware/fingerprint/FingerprintManager.java b/core/java/android/hardware/fingerprint/FingerprintManager.java
index 6df2764d3f8b..2e4063b6dec1 100644
--- a/core/java/android/hardware/fingerprint/FingerprintManager.java
+++ b/core/java/android/hardware/fingerprint/FingerprintManager.java
@@ -114,6 +114,21 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
      */
     public static final int SENSOR_ID_ANY = -1;
 
+    private static class RemoveTracker {
+        static final int REMOVE_SINGLE = 1;
+        static final int REMOVE_ALL = 2;
+        @IntDef({REMOVE_SINGLE, REMOVE_ALL})
+        @interface RemoveRequest {}
+
+        final @RemoveRequest int mRemoveRequest;
+        @Nullable final Fingerprint mSingleFingerprint;
+
+        RemoveTracker(@RemoveRequest int request, @Nullable Fingerprint fingerprint) {
+            mRemoveRequest = request;
+            mSingleFingerprint = fingerprint;
+        }
+    }
+
     private IFingerprintService mService;
     private Context mContext;
     private IBinder mToken = new Binder();
@@ -123,10 +138,9 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
     private RemovalCallback mRemovalCallback;
     private GenerateChallengeCallback mGenerateChallengeCallback;
     private CryptoObject mCryptoObject;
-    private Fingerprint mRemovalFingerprint;
+    @Nullable private RemoveTracker mRemoveTracker;
     private Handler mHandler;
 
-
     /**
      * Retrieves a list of properties for all fingerprint sensors on the device.
      * @hide
@@ -735,7 +749,7 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
     public void remove(Fingerprint fp, int userId, RemovalCallback callback) {
         if (mService != null) try {
             mRemovalCallback = callback;
-            mRemovalFingerprint = fp;
+            mRemoveTracker = new RemoveTracker(RemoveTracker.REMOVE_SINGLE, fp);
             mService.remove(mToken, fp.getBiometricId(), userId, mServiceReceiver,
                     mContext.getOpPackageName());
         } catch (RemoteException e) {
@@ -752,6 +766,7 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
         if (mService != null) {
             try {
                 mRemovalCallback = callback;
+                mRemoveTracker = new RemoveTracker(RemoveTracker.REMOVE_ALL, null /* fp */);
                 mService.removeAll(mToken, userId, mServiceReceiver, mContext.getOpPackageName());
             } catch (RemoteException e) {
                 throw e.rethrowFromSystemServer();
@@ -1055,16 +1070,29 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
         if (mRemovalCallback == null) {
             return;
         }
-        if (fingerprint == null) {
-            Slog.e(TAG, "Received MSG_REMOVED, but fingerprint is null");
+
+        if (mRemoveTracker == null) {
+            Slog.w(TAG, "Removal tracker is null");
             return;
         }
 
-        int fingerId = fingerprint.getBiometricId();
-        int reqFingerId = mRemovalFingerprint.getBiometricId();
-        if (reqFingerId != 0 && fingerId != 0 && fingerId != reqFingerId) {
-            Slog.w(TAG, "Finger id didn't match: " + fingerId + " != " + reqFingerId);
-            return;
+        if (mRemoveTracker.mRemoveRequest == RemoveTracker.REMOVE_SINGLE) {
+            if (fingerprint == null) {
+                Slog.e(TAG, "Received MSG_REMOVED, but fingerprint is null");
+                return;
+            }
+
+            if (mRemoveTracker.mSingleFingerprint == null) {
+                Slog.e(TAG, "Missing fingerprint");
+                return;
+            }
+
+            final int fingerId = fingerprint.getBiometricId();
+            int reqFingerId = mRemoveTracker.mSingleFingerprint.getBiometricId();
+            if (reqFingerId != 0 && fingerId != 0 && fingerId != reqFingerId) {
+                Slog.w(TAG, "Finger id didn't match: " + fingerId + " != " + reqFingerId);
+                return;
+            }
         }
 
         mRemovalCallback.onRemovalSucceeded(fingerprint, remaining);
@@ -1121,7 +1149,9 @@ public class FingerprintManager implements BiometricAuthenticator, BiometricFing
             mAuthenticationCallback.onAuthenticationError(clientErrMsgId,
                     getErrorString(mContext, errMsgId, vendorCode));
         } else if (mRemovalCallback != null) {
-            mRemovalCallback.onRemovalError(mRemovalFingerprint, clientErrMsgId,
+            final Fingerprint fp = mRemoveTracker != null
+                    ? mRemoveTracker.mSingleFingerprint : null;
+            mRemovalCallback.onRemovalError(fp, clientErrMsgId,
                     getErrorString(mContext, errMsgId, vendorCode));
         }
     }