Question

I have implemented SyncAdapter to perform sync of items in application. This adapter is invoked correctly by Android when sync is requested either programmatically or automatically.

When I try to cancel the sync operation manually by deselecting the check box under Accounts and sync setting >{myappccount} > Data and Synchronisation > {app item} , my sync adapters onSyncCanceled is also get called correctly.

But when I my app try to read some internal setting through content provider query , it receives “java.lang.SecurityException: Permission Denial”. Although same query works well during normal execution of application or during sync .

Below is stack trace.

java.lang.SecurityException: Permission Denial: reading com.my.applications.sync.content.MySettingProvider uri content://com.my.applications.sync.provider.mysetting/currentstateid from pid=0, uid=1000 requires null
at android.content.ContentProvider$Transport.enforceReadPermission(ContentProvider.java:307)
at android.content.ContentProvider$Transport.query(ContentProvider.java:186)
at android.content.ContentResolver.query(ContentResolver.java:262)
at com.my.applications.sync.service.MysyncService.getCurrentServiceUri(MysyncService.java:442)
at com.my.applications.sync.service.MysyncService.cancelSync(MysyncService.java:1723)
at com.my.applications.sync.syncadapter.OtherSyncAdapter.onSyncCanceled(OtherSyncAdapter.java:51)
at android.content.AbstractThreadedSyncAdapter$ISyncAdapterImpl.cancelSync(AbstractThreadedSyncAdapter.java:121)
at android.content.ISyncAdapter$Stub.onTransact(ISyncAdapter.java:78)
at android.os.Binder.execTransact(Binder.java:320)
at dalvik.system.NativeStart.run(Native Method)

Do I need to add any permission for my internal content provider?

Answer 1

It looks from your stack trace that you’ve declared a readPermission on your ContentProvider. When onSyncCanceled(..) is called on your app it’s an RPC call from the sync manager (typically) – and the Sync manager is not likely to hold the readPermission.

Try the following in #onCancelSync(..) to run your cancel code without the callers pid/uid involved:

long caller = android.os.Binder.clearCallingIdentity();
try {
// Do your stuff here
} finally {
   android.os.Binder.restoreCallingIdentity(caller);
}

Br,
Jens