From 6c93075645c1c022c96a46ecf54e83a3d6abc174 Mon Sep 17 00:00:00 2001
From: paulhu <paulhu@google.com>
Date: Mon, 16 Dec 2019 18:24:05 +0800
Subject: [PATCH] Fix security problem on PermissionMonitor#hasPermission

PermissionMonitor#hasPermission only checks permssions that app
requested but it doesn't check whether the permission can be
granted to this app. If requested permission doens't be granted
to app, this method still returns that app has this permission.
Then PermissionMonitor will pass this info to netd that means
this app still can use network even restricted network without
granted privileged permission like CONNECTIVITY_INTERNAL or
CONNECTIVITY_USE_RESTRICTED_NETWORKS.

Bug: 144679405
Test: Build, flash, manual test
Change-Id: Iae9c273af822b18c2e6fce04848a86f8dea6410a
Merged-In: I8a1575dedd6e3b7a8b60ee2ffd475d790aec55c4
Merged-In: I2da730feda4d7ebed1f158b073167bb3964b3e7d
---
 .../server/connectivity/PermissionMonitor.java   | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/services/core/java/com/android/server/connectivity/PermissionMonitor.java b/services/core/java/com/android/server/connectivity/PermissionMonitor.java
index e471c7d84b..5722f5a72a 100644
--- a/services/core/java/com/android/server/connectivity/PermissionMonitor.java
+++ b/services/core/java/com/android/server/connectivity/PermissionMonitor.java
@@ -22,6 +22,7 @@ import static android.Manifest.permission.CONNECTIVITY_USE_RESTRICTED_NETWORKS;
 import static android.Manifest.permission.NETWORK_STACK;
 import static android.content.pm.ApplicationInfo.FLAG_SYSTEM;
 import static android.content.pm.ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;
+import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
 
 import android.content.BroadcastReceiver;
@@ -42,6 +43,7 @@ import android.text.TextUtils;
 import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.ArrayUtils;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -161,15 +163,13 @@ public class PermissionMonitor {
     }
 
     @VisibleForTesting
-    boolean hasPermission(PackageInfo app, String permission) {
-        if (app.requestedPermissions != null) {
-            for (String p : app.requestedPermissions) {
-                if (permission.equals(p)) {
-                    return true;
-                }
-            }
+    boolean hasPermission(final PackageInfo app, final String permission) {
+        if (app.requestedPermissions == null || app.requestedPermissionsFlags == null) {
+            return false;
         }
-        return false;
+        final int index = ArrayUtils.indexOf(app.requestedPermissions, permission);
+        if (index < 0 || index >= app.requestedPermissionsFlags.length) return false;
+        return (app.requestedPermissionsFlags[index] & REQUESTED_PERMISSION_GRANTED) != 0;
     }
 
     private boolean hasNetworkPermission(PackageInfo app) {