diff --git a/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceController.java b/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceController.java
index 0767e65..6bee62c 100644
--- a/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceController.java
+++ b/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceController.java
@@ -81,6 +81,8 @@
         final RestrictedSwitchPreference preference =
                 (RestrictedSwitchPreference) pref;
         final CharSequence label = mPkgInfo.applicationInfo.loadLabel(mPm);
+        final boolean isAllowedCn = mCn.flattenToShortString().length()
+                <= NotificationManager.MAX_SERVICE_COMPONENT_NAME_LENGTH;
         final boolean isEnabled = isServiceEnabled(mCn);
         preference.setChecked(isEnabled);
         preference.setOnPreferenceChangeListener((p, newValue) -> {
@@ -105,7 +107,8 @@
                 return false;
             }
         });
-        preference.updateState(mCn.getPackageName(), mPkgInfo.applicationInfo.uid, isEnabled);
+        preference.updateState(
+                mCn.getPackageName(), mPkgInfo.applicationInfo.uid, isAllowedCn, isEnabled);
     }
 
     public void disable(final ComponentName cn) {
diff --git a/src/com/android/settings/notification/NotificationAccessConfirmationActivity.java b/src/com/android/settings/notification/NotificationAccessConfirmationActivity.java
index dfe6df2..a6b565a 100644
--- a/src/com/android/settings/notification/NotificationAccessConfirmationActivity.java
+++ b/src/com/android/settings/notification/NotificationAccessConfirmationActivity.java
@@ -67,7 +67,9 @@
         mUserId = getIntent().getIntExtra(EXTRA_USER_ID, UserHandle.USER_NULL);
         CharSequence mAppLabel;
 
-        if (mComponentName == null || mComponentName.getPackageName() == null) {
+        if (mComponentName == null || mComponentName.getPackageName() == null
+                || mComponentName.flattenToString().length()
+                > NotificationManager.MAX_SERVICE_COMPONENT_NAME_LENGTH) {
             finish();
             return;
         }
diff --git a/src/com/android/settings/notification/NotificationAccessSettings.java b/src/com/android/settings/notification/NotificationAccessSettings.java
index 369c4f6..e2ef0dd 100644
--- a/src/com/android/settings/notification/NotificationAccessSettings.java
+++ b/src/com/android/settings/notification/NotificationAccessSettings.java
@@ -66,7 +66,6 @@
     private static final String TAG = "NotifAccessSettings";
     static final String ALLOWED_KEY = "allowed";
     static final String NOT_ALLOWED_KEY = "not_allowed";
-    private static final int MAX_CN_LENGTH = 500;
 
     private static final ManagedServiceSettings.Config CONFIG =
             new ManagedServiceSettings.Config.Builder()
@@ -150,7 +149,8 @@
         for (ServiceInfo service : services) {
             final ComponentName cn = new ComponentName(service.packageName, service.name);
             boolean isAllowed = mNm.isNotificationListenerAccessGranted(cn);
-            if (!isAllowed && cn.flattenToString().length() > MAX_CN_LENGTH) {
+            if (!isAllowed && cn.flattenToString().length()
+                    > NotificationManager.MAX_SERVICE_COMPONENT_NAME_LENGTH) {
                 continue;
             }
 
diff --git a/tests/unit/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceControllerTest.java b/tests/unit/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceControllerTest.java
index 249b713..4601a1c 100644
--- a/tests/unit/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceControllerTest.java
+++ b/tests/unit/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceControllerTest.java
@@ -84,6 +84,36 @@
     }
 
     @Test
+    public void updateState_enabled() {
+        when(mAppOpsManager.noteOpNoThrow(anyInt(), anyInt(), anyString())).thenReturn(
+                AppOpsManager.MODE_ALLOWED);
+        when(mNm.isNotificationListenerAccessGranted(mCn)).thenReturn(true);
+        RestrictedSwitchPreference pref = new RestrictedSwitchPreference(
+                mContext);
+        pref.setAppOps(mAppOpsManager);
+
+        mController.updateState(pref);
+
+        assertThat(pref.isEnabled()).isTrue();
+    }
+
+    @Test
+    public void updateState_invalidCn_disabled() {
+        ComponentName longCn = new ComponentName("com.example.package",
+                com.google.common.base.Strings.repeat("Blah", 150));
+        mController.setCn(longCn);
+        when(mAppOpsManager.noteOpNoThrow(anyInt(), anyInt(), anyString())).thenReturn(
+                AppOpsManager.MODE_ALLOWED);
+        RestrictedSwitchPreference pref = new RestrictedSwitchPreference(
+                mContext);
+        pref.setAppOps(mAppOpsManager);
+
+        mController.updateState(pref);
+
+        assertThat(pref.isEnabled()).isFalse();
+    }
+
+    @Test
     public void updateState_checked() {
         when(mAppOpsManager.noteOpNoThrow(anyInt(), anyInt(), anyString())).thenReturn(
                 AppOpsManager.MODE_ALLOWED);