commit 10d8a114bbd91c07f2feb5009328b16203ff50b1
author Dmitry Dementyev <dementyev@google.com> Tue Nov 10 16:01:35 2020 -0800
committer Dmitry Dementyev <dementyev@google.com> Tue Nov 10 16:05:58 2020 -0800
tree 4d74103311b8d8542e4c985050fa015c997983e8
parent 1d3492e18196f57661ec92a20af0ae028a680ecf

Ignore GrantCredentials call with unexpected calling uid.

Activity can be used only in two cases.
1) Calling uid matches uid grantee.
2) Calling uid is is system. This flow is used by getToken methods with
notifyAuthFailure=true.

Test: Existing CTS tests
Bug: 158480899
Change-Id: I1421c333b6cebb4f7cddcdd8766298f6872e933b

core/java/android/accounts/GrantCredentialsPermissionActivity.java

diff --git a/core/java/android/accounts/GrantCredentialsPermissionActivity.java b/core/java/android/accounts/GrantCredentialsPermissionActivity.java
index af74b03..42bd80b 100644
--- a/core/java/android/accounts/GrantCredentialsPermissionActivity.java
+++ b/core/java/android/accounts/GrantCredentialsPermissionActivity.java
@@ -16,16 +16,23 @@
 package android.accounts;
 
 import android.app.Activity;
-import android.content.res.Resources;
-import android.os.Bundle;
-import android.widget.TextView;
-import android.widget.LinearLayout;
-import android.view.View;
-import android.view.LayoutInflater;
+import android.app.ActivityTaskManager;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
+import android.content.res.Resources;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.os.Process;
+import android.os.RemoteException;
+import android.os.UserHandle;
 import android.text.TextUtils;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+
 import com.android.internal.R;
 
 import java.io.IOException;
@@ -42,6 +49,7 @@
     private Account mAccount;
     private String mAuthTokenType;
     private int mUid;
+    private int mCallingUid;
     private Bundle mResultBundle = null;
     protected LayoutInflater mInflater;
 
@@ -74,6 +82,20 @@
             return;
         }
 
+        try {
+            IBinder activityToken = getActivityToken();
+            mCallingUid = ActivityTaskManager.getService().getLaunchedFromUid(activityToken);
+        } catch (RemoteException re) {
+            // Couldn't figure out caller details
+            Log.w(getClass().getSimpleName(), "Unable to get caller identity \n" + re);
+        }
+
+        if (!UserHandle.isSameApp(mCallingUid, Process.SYSTEM_UID) && mCallingUid != mUid) {
+            setResult(Activity.RESULT_CANCELED);
+            finish();
+            return;
+        }
+
         String accountTypeLabel;
         try {
             accountTypeLabel = getAccountLabel(mAccount);