[SOLVED] Android 14 BAL Hardening Warning for PendingIntent in Wear OS (Target SDK 34+)

Android 14 BAL Hardening Warning for PendingIntent in Wear OS (Target SDK 34+)

I’m developing a standalone timer app for Wear OS with targetSdk 35. The app has an ongoingActivity notification and a watch face complication. When the user taps the notification or the complication, it should open the app via a PendingIntent.

Everything is working correctly, but I see the following warning in the logs:

"With Android 14 BAL hardening, this activity start will be blocked if the PI sender upgrades target_sdk to 34+! (missing opt-in by PI sender)!" [callingPackage: com.example.timer; callingPackageTargetSdk: 35; callingUid: 10083; callingPid: -1; appSwitchState: 2; callingUidHasAnyVisibleWindow: false; callingUidProcState: FOREGROUND_SERVICE; isCallingUidPersistentSystemProcess: false; forcedBalByPiSender: BSP.NONE; intent: Intent { cmp=com.example.timer/.presentation.ui.MainActivity }; callerApp: null; balAllowedByPiCreator: BSP.ALLOW_BAL; balAllowedByPiCreatorWithHardening: BSP.ALLOW_BAL; resultIfPiCreatorAllowsBal: BAL_BLOCK; callerStartMode: MODE_BACKGROUND_ACTIVITY_START_SYSTEM_DEFINED; hasRealCaller: true; isCallForResult: false; isPendingIntent: true; autoOptInReason: null; realCallingPackage: com.google.android.wearable.sysui; realCallingPackageTargetSdk: 33; realCallingUid: 10020; realCallingPid: 970; realCallingUidHasAnyVisibleWindow: true; realCallingUidProcState: TOP; isRealCallingUidPersistentSystemProcess: false; originatingPendingIntent: PendingIntentRecord{6fcd2d6 com.example.timer startActivity (allowlist: 289f7e5:+30s0ms/0/NOTIFICATION_SERVICE/NotificationManagerService)}; realCallerApp: ProcessRecord{9c7f6f7 970:com.google.android.wearable.sysui/u0a20}; realInVisibleTask: true; balAllowedByPiSender: BSP.ALLOW_BAL; resultIfPiSenderAllowsBal: BAL_ALLOW_VISIBLE_WINDOW; realCallerStartMode: MODE_BACKGROUND_ACTIVITY_START_ALLOWED; balImproveRealCallerVisibilityCheck: true; balRequireOptInByPendingIntentCreator: true; balRequireOptInSameUid: false; balRespectAppSwitchStateWhenCheckBoundByForegroundUid: true; balDontBringExistingBackgroundTaskStackToFg: true]

Based on the Android background activity starts documentation, I expected that using:

val activityOptions = ActivityOptions.makeBasic().apply {
    setPendingIntentCreatorBackgroundActivityStartMode(
        ActivityOptions.MODE_BACKGROUND_ACTIVITY_START_ALLOWED
    )
}

val launchActivityPendingIntent: PendingIntent = PendingIntent.getActivity(
    this,
    0,
    Intent(this, MainActivity::class.java),
    PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
    activityOptions.toBundle() // Attempted to resolve the warning
)

would resolve the warning, but it still appears in the logs.

Question:

Is this warning expected even if the PendingIntent works?
How can I properly opt in to avoid this warning when targeting SDK 34+? Any insights would be appreciated!

Solution

Running the app on the newly released Wear OS 6 beta (API 36, based on Android 16) solves the issue. The warning no longer appears, which is the expected behavior. On Wear OS 5.1 (API 35) the error stills appears, so I assume Google fixed it in the new version only.