From 87944e742cea0890f686126fd8e706a11c6155d2 Mon Sep 17 00:00:00 2001
From: Rhed Jao <rhedjao@google.com>
Date: Tue, 10 May 2022 15:50:51 +0800
Subject: [PATCH] Using isUidPrivileged instead of getPrivateFlagsForUid API

Starting from U, the PackageManager#getPrivateFlagsForUid does
not support to get private flags for different users. It
returns nothing if the package cannot be found in the calling
user.

To avoid failing to get private flags in the IntentFirewall,
this CL uses the internal API isUidPrivileged to check the
privilege state of the caller.

Bug: 229684723
Test: Build
Change-Id: I8440cb51e4318d57a097efe651be626b9df2da0f
---
 .../server/firewall/IntentFirewall.java       |  4 +--
 .../android/server/firewall/SenderFilter.java | 27 +++++--------------
 2 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/services/core/java/com/android/server/firewall/IntentFirewall.java b/services/core/java/com/android/server/firewall/IntentFirewall.java
index c8a3ee6b1be6e..2b95b11a09cd4 100644
--- a/services/core/java/com/android/server/firewall/IntentFirewall.java
+++ b/services/core/java/com/android/server/firewall/IntentFirewall.java
@@ -130,7 +130,7 @@ public class IntentFirewall {
         mObserver.startWatching();
     }
 
-    private PackageManagerInternal getPackageManager() {
+    PackageManagerInternal getPackageManager() {
         if (mPackageManager == null) {
             mPackageManager = LocalServices.getService(PackageManagerInternal.class);
         }
@@ -627,7 +627,7 @@ public class IntentFirewall {
         final long token = Binder.clearCallingIdentity();
         try {
             // Compare signatures of two packages for different users.
-            return LocalServices.getService(PackageManagerInternal.class)
+            return getPackageManager()
                     .checkUidSignaturesForAllUsers(uid1, uid2) == PackageManager.SIGNATURE_MATCH;
         } finally {
             Binder.restoreCallingIdentity(token);
diff --git a/services/core/java/com/android/server/firewall/SenderFilter.java b/services/core/java/com/android/server/firewall/SenderFilter.java
index 0074119623298..40684fab5c70a 100644
--- a/services/core/java/com/android/server/firewall/SenderFilter.java
+++ b/services/core/java/com/android/server/firewall/SenderFilter.java
@@ -16,14 +16,11 @@
 
 package com.android.server.firewall;
 
-import android.app.AppGlobals;
 import android.content.ComponentName;
 import android.content.Intent;
-import android.content.pm.ApplicationInfo;
-import android.content.pm.IPackageManager;
+import android.content.pm.PackageManagerInternal;
 import android.os.Process;
-import android.os.RemoteException;
-import android.util.Slog;
+
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 
@@ -37,22 +34,12 @@ class SenderFilter {
     private static final String VAL_SYSTEM_OR_SIGNATURE = "system|signature";
     private static final String VAL_USER_ID = "userId";
 
-    static boolean isPrivilegedApp(int callerUid, int callerPid) {
+    static boolean isPrivilegedApp(PackageManagerInternal pmi, int callerUid, int callerPid) {
         if (callerUid == Process.SYSTEM_UID || callerUid == 0 ||
                 callerPid == Process.myPid() || callerPid == 0) {
             return true;
         }
-
-        IPackageManager pm = AppGlobals.getPackageManager();
-        try {
-            return (pm.getPrivateFlagsForUid(callerUid) & ApplicationInfo.PRIVATE_FLAG_PRIVILEGED)
-                    != 0;
-        } catch (RemoteException ex) {
-            Slog.e(IntentFirewall.TAG, "Remote exception while retrieving uid flags",
-                    ex);
-        }
-
-        return false;
+        return pmi.isUidPrivileged(callerUid);
     }
 
     public static final FilterFactory FACTORY = new FilterFactory("sender") {
@@ -89,7 +76,7 @@ class SenderFilter {
         @Override
         public boolean matches(IntentFirewall ifw, ComponentName resolvedComponent, Intent intent,
                 int callerUid, int callerPid, String resolvedType, int receivingUid) {
-            return isPrivilegedApp(callerUid, callerPid);
+            return isPrivilegedApp(ifw.getPackageManager(), callerUid, callerPid);
         }
     };
 
@@ -97,8 +84,8 @@ class SenderFilter {
         @Override
         public boolean matches(IntentFirewall ifw, ComponentName resolvedComponent, Intent intent,
                 int callerUid, int callerPid, String resolvedType, int receivingUid) {
-            return isPrivilegedApp(callerUid, callerPid) ||
-                    ifw.signaturesMatch(callerUid, receivingUid);
+            return isPrivilegedApp(ifw.getPackageManager(), callerUid, callerPid)
+                    || ifw.signaturesMatch(callerUid, receivingUid);
         }
     };