If we can't get the restore set's metadata, don't continue

Without the metadata we can't verify the version number or the signatures of the
apps whose data we'd be trying to restore against the apps present on device.
This is not acceptable; we need to refuse to give data to an unauthenticated
app.

1 files changed, 9 insertions, 0 deletions

diff --git a/services/java/com/android/server/BackupManagerService.java b/services/java/com/android/server/BackupManagerService.java
index c3b9157..7977d1f 100644
--- a/services/java/com/android/server/BackupManagerService.java
+++ b/services/java/com/android/server/BackupManagerService.java
@@ -943,6 +943,15 @@ class BackupManagerService extends IBackupManager.Stub {
                         mPackageManager, agentPackages);
                 processOneRestore(omPackage, 0, IBackupAgent.Stub.asInterface(pmAgent.onBind()));
 
+                // Verify that the backup set includes metadata.  If not, we can't do
+                // signature/version verification etc, so we simply do not proceed with
+                // the restore operation.
+                Metadata pmMeta = pmAgent.getRestoredMetadata(packageName);
+                if (pmMeta == null) {
+                    Log.i(TAG, "No restore metadata available, so not restoring settings");
+                    return;
+                }
+
                 int count = 0;
                 for (;;) {
                     packageName = mTransport.nextRestorePackage();