diff --git a/services/core/java/com/android/server/fingerprint/AuthenticationClient.java b/services/core/java/com/android/server/fingerprint/AuthenticationClient.java
index afd1a94bf5069..61bc843aad795 100644
--- a/services/core/java/com/android/server/fingerprint/AuthenticationClient.java
+++ b/services/core/java/com/android/server/fingerprint/AuthenticationClient.java
@@ -16,7 +16,15 @@
 
 package com.android.server.fingerprint;
 
+import static android.Manifest.permission.USE_BIOMETRIC;
+import static android.Manifest.permission.USE_FINGERPRINT;
+
+import android.app.ActivityManager;
+import android.app.IActivityManager;
+import android.content.ComponentName;
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
 import android.hardware.biometrics.fingerprint.V2_1.IBiometricsFingerprint;
 import android.hardware.biometrics.BiometricPrompt;
 import android.hardware.biometrics.IBiometricPromptReceiver;
@@ -26,12 +34,16 @@ import android.hardware.fingerprint.IFingerprintServiceReceiver;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.os.RemoteException;
+import android.util.EventLog;
 import android.util.Slog;
 
+import com.android.internal.R;
 import com.android.internal.logging.MetricsLogger;
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.internal.statusbar.IStatusBarService;
 
+import java.util.List;
+
 /**
  * A class to keep track of the authentication state for a given client.
  */
@@ -156,10 +168,68 @@ public abstract class AuthenticationClient extends ClientMonitor {
         boolean result = false;
         boolean authenticated = fingerId != 0;
 
+        // Ensure authentication only succeeds if the client activity is on top or is keyguard.
+        boolean isBackgroundAuth = false;
+        if (authenticated && !isKeyguard(getContext(), getOwnerString())) {
+            final ActivityManager activityManager =
+                    (ActivityManager) getContext().getSystemService(Context.ACTIVITY_SERVICE);
+            final IActivityManager activityManagerService = activityManager != null
+                    ? activityManager.getService()
+                    : null;
+            if (activityManagerService == null) {
+                Slog.e(TAG, "Unable to get activity manager service");
+                isBackgroundAuth = true;
+            } else {
+                try {
+                    final List<ActivityManager.RunningTaskInfo> tasks =
+                            activityManagerService.getTasks(1);
+                    if (tasks == null || tasks.isEmpty()) {
+                        Slog.e(TAG, "No running tasks reported");
+                        isBackgroundAuth = true;
+                    } else {
+                        final ComponentName topActivity = tasks.get(0).topActivity;
+                        if (topActivity == null) {
+                            Slog.e(TAG, "Unable to get top activity");
+                            isBackgroundAuth = true;
+                        } else {
+                            final String topPackage = topActivity.getPackageName();
+                            if (!topPackage.contentEquals(getOwnerString())) {
+                                Slog.e(TAG, "Background authentication detected, top: " + topPackage
+                                        + ", client: " + this);
+                                isBackgroundAuth = true;
+                            }
+                        }
+                    }
+                } catch (RemoteException e) {
+                    Slog.e(TAG, "Unable to get running tasks", e);
+                    isBackgroundAuth = true;
+                }
+            }
+        }
+
+        // Fail authentication if we can't confirm the client activity is on top.
+        if (isBackgroundAuth) {
+            Slog.e(TAG, "Failing possible background authentication");
+            authenticated = false;
+
+            // SafetyNet logging for exploitation attempts of b/159249069.
+            final ApplicationInfo appInfo = getContext().getApplicationInfo();
+            EventLog.writeEvent(0x534e4554, "159249069", appInfo != null ? appInfo.uid : -1,
+                    "Attempted background authentication");
+        }
+
         // If the fingerprint dialog is showing, notify authentication succeeded
         if (mBundle != null) {
             try {
                 if (authenticated) {
+                    // SafetyNet logging for b/159249069 if constraint is violated.
+                    if (isBackgroundAuth) {
+                        final ApplicationInfo appInfo = getContext().getApplicationInfo();
+                        EventLog.writeEvent(0x534e4554, "159249069",
+                                appInfo != null ? appInfo.uid : -1,
+                                "Successful background authentication! Dialog notified");
+                    }
+
                     mStatusBarService.onFingerprintAuthenticated();
                 } else {
                     mStatusBarService.onFingerprintHelp(getContext().getResources().getString(
@@ -178,6 +248,14 @@ public abstract class AuthenticationClient extends ClientMonitor {
                 if (!authenticated) {
                     receiver.onAuthenticationFailed(getHalDeviceId());
                 } else {
+                    // SafetyNet logging for b/159249069 if constraint is violated.
+                    if (isBackgroundAuth) {
+                        final ApplicationInfo appInfo = getContext().getApplicationInfo();
+                        EventLog.writeEvent(0x534e4554, "159249069",
+                                appInfo != null ? appInfo.uid : -1,
+                                "Successful background authentication! Receiver notified");
+                    }
+
                     if (DEBUG) {
                         Slog.v(TAG, "onAuthenticated(owner=" + getOwnerString()
                                 + ", id=" + fingerId + ", gp=" + groupId + ")");
@@ -226,6 +304,13 @@ public abstract class AuthenticationClient extends ClientMonitor {
             }
             result |= lockoutMode != LOCKOUT_NONE; // in a lockout mode
         } else {
+            // SafetyNet logging for b/159249069 if constraint is violated.
+            if (isBackgroundAuth) {
+                final ApplicationInfo appInfo = getContext().getApplicationInfo();
+                EventLog.writeEvent(0x534e4554, "159249069", appInfo != null ? appInfo.uid : -1,
+                        "Successful background authentication! Lockout reset");
+            }
+
             if (receiver != null) {
                 vibrateSuccess();
             }
@@ -236,6 +321,20 @@ public abstract class AuthenticationClient extends ClientMonitor {
         return result;
     }
 
+    private static boolean isKeyguard(Context context, String clientPackage) {
+        final boolean hasFingerPermission = context.checkCallingOrSelfPermission(USE_FINGERPRINT)
+                    == PackageManager.PERMISSION_GRANTED;
+        final boolean hasBiometricPermission = context.checkCallingOrSelfPermission(USE_BIOMETRIC)
+                    == PackageManager.PERMISSION_GRANTED;
+        final boolean hasPermission = hasFingerPermission || hasBiometricPermission;
+
+        final ComponentName keyguardComponent = ComponentName.unflattenFromString(
+                context.getResources().getString(R.string.config_keyguardComponent));
+        final String keyguardPackage = keyguardComponent != null
+                ? keyguardComponent.getPackageName() : null;
+        return hasPermission && keyguardPackage != null && keyguardPackage.equals(clientPackage);
+    }
+
     /**
      * Start authentication
      */