diff --git a/service/src/com/android/server/connectivity/PermissionMonitor.java b/service/src/com/android/server/connectivity/PermissionMonitor.java
old mode 100644
new mode 100755
index 3328846..e98a638
--- a/service/src/com/android/server/connectivity/PermissionMonitor.java
+++ b/service/src/com/android/server/connectivity/PermissionMonitor.java
@@ -230,11 +230,11 @@
             boolean hasRestrictedPermission = hasRestrictedNetworkPermission(app);
 
             if (isNetwork || hasRestrictedPermission) {
-                Boolean permission = mApps.get(uid);
+                Boolean permission = mApps.get(UserHandle.getAppId(uid));
                 // If multiple packages share a UID (cf: android:sharedUserId) and ask for different
                 // permissions, don't downgrade (i.e., if it's already SYSTEM, leave it as is).
                 if (permission == null || permission == NETWORK) {
-                    mApps.put(uid, hasRestrictedPermission);
+                    mApps.put(UserHandle.getAppId(uid), hasRestrictedPermission);
                 }
             }
 
@@ -325,14 +325,14 @@
         // networks. mApps contains the result of checks for both hasNetworkPermission and
         // hasRestrictedNetworkPermission. If uid is in the mApps list that means uid has one of
         // permissions at least.
-        return mApps.containsKey(uid);
+        return mApps.containsKey(UserHandle.getAppId(uid));
     }
 
     /**
      * Returns whether the given uid has permission to use restricted networks.
      */
     public synchronized boolean hasRestrictedNetworksPermission(int uid) {
-        return Boolean.TRUE.equals(mApps.get(uid));
+        return Boolean.TRUE.equals(mApps.get(UserHandle.getAppId(uid)));
     }
 
     private void update(Set<UserHandle> users, Map<Integer, Boolean> apps, boolean add) {
@@ -452,12 +452,13 @@
 
         // If multiple packages share a UID (cf: android:sharedUserId) and ask for different
         // permissions, don't downgrade (i.e., if it's already SYSTEM, leave it as is).
-        final Boolean permission = highestPermissionForUid(mApps.get(uid), packageName);
-        if (permission != mApps.get(uid)) {
-            mApps.put(uid, permission);
+        final int appId = UserHandle.getAppId(uid);
+        final Boolean permission = highestPermissionForUid(mApps.get(appId), packageName);
+        if (permission != mApps.get(appId)) {
+            mApps.put(appId, permission);
 
             Map<Integer, Boolean> apps = new HashMap<>();
-            apps.put(uid, permission);
+            apps.put(appId, permission);
             update(mUsers, apps, true);
         }
 
@@ -472,7 +473,7 @@
                 updateVpnUids(vpn.getKey(), changedUids, true);
             }
         }
-        mAllApps.add(UserHandle.getAppId(uid));
+        mAllApps.add(appId);
     }
 
     private Boolean highestUidNetworkPermission(int uid) {
@@ -529,16 +530,17 @@
             return;
         }
 
-        if (permission == mApps.get(uid)) {
+        final int appId = UserHandle.getAppId(uid);
+        if (permission == mApps.get(appId)) {
             // The permissions of this UID have not changed. Nothing to do.
             return;
         } else if (permission != null) {
-            mApps.put(uid, permission);
-            apps.put(uid, permission);
+            mApps.put(appId, permission);
+            apps.put(appId, permission);
             update(mUsers, apps, true);
         } else {
-            mApps.remove(uid);
-            apps.put(uid, NETWORK);  // doesn't matter which permission we pick here
+            mApps.remove(appId);
+            apps.put(appId, NETWORK);  // doesn't matter which permission we pick here
             update(mUsers, apps, false);
         }
     }
@@ -653,7 +655,7 @@
      */
     private void removeBypassingUids(Set<Integer> uids, int vpnAppUid) {
         uids.remove(vpnAppUid);
-        uids.removeIf(uid -> mApps.getOrDefault(uid, NETWORK) == SYSTEM);
+        uids.removeIf(uid -> mApps.getOrDefault(UserHandle.getAppId(uid), NETWORK) == SYSTEM);
     }
 
     /**
@@ -795,12 +797,13 @@
         for (Integer uid : uidsToUpdate) {
             final Boolean permission = highestUidNetworkPermission(uid);
 
+            final int appId = UserHandle.getAppId(uid);
             if (null == permission) {
-                removedUids.put(uid, NETWORK); // Doesn't matter which permission is set here.
-                mApps.remove(uid);
+                removedUids.put(appId, NETWORK); // Doesn't matter which permission is set here.
+                mApps.remove(appId);
             } else {
-                updatedUids.put(uid, permission);
-                mApps.put(uid, permission);
+                updatedUids.put(appId, permission);
+                mApps.put(appId, permission);
             }
         }
 
diff --git a/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java b/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
index e98f5db..db63495 100644
--- a/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
+++ b/tests/unit/java/com/android/server/connectivity/PermissionMonitorTest.java
@@ -521,13 +521,13 @@
         // MOCK_UID1: MOCK_PACKAGE1 only has network permission.
         // SYSTEM_UID: SYSTEM_PACKAGE1 has system permission.
         // SYSTEM_UID: SYSTEM_PACKAGE2 only has network permission.
-        doReturn(SYSTEM).when(mPermissionMonitor).highestPermissionForUid(eq(SYSTEM), anyString());
         doReturn(SYSTEM).when(mPermissionMonitor).highestPermissionForUid(any(),
                 eq(SYSTEM_PACKAGE1));
         doReturn(NETWORK).when(mPermissionMonitor).highestPermissionForUid(any(),
                 eq(SYSTEM_PACKAGE2));
         doReturn(NETWORK).when(mPermissionMonitor).highestPermissionForUid(any(),
                 eq(MOCK_PACKAGE1));
+        doReturn(SYSTEM).when(mPermissionMonitor).highestPermissionForUid(eq(SYSTEM), anyString());
 
         // Add SYSTEM_PACKAGE2, expect only have network permission.
         mPermissionMonitor.onUserAdded(MOCK_USER1);
@@ -542,6 +542,21 @@
         netdMonitor.expectPermission(SYSTEM, new UserHandle[]{MOCK_USER1, MOCK_USER2},
                 new int[]{SYSTEM_UID});
 
+        // Remove SYSTEM_PACKAGE2, expect keep system permission.
+        when(mPackageManager.getPackagesForUid(MOCK_USER1.getUid(SYSTEM_UID)))
+                .thenReturn(new String[]{SYSTEM_PACKAGE1});
+        when(mPackageManager.getPackagesForUid(MOCK_USER2.getUid(SYSTEM_UID)))
+                .thenReturn(new String[]{SYSTEM_PACKAGE1});
+        removePackageForUsers(new UserHandle[]{MOCK_USER1, MOCK_USER2},
+                SYSTEM_PACKAGE2, SYSTEM_UID);
+        netdMonitor.expectPermission(SYSTEM, new UserHandle[]{MOCK_USER1, MOCK_USER2},
+                new int[]{SYSTEM_UID});
+
+        // Add SYSTEM_PACKAGE2, expect keep system permission.
+        addPackageForUsers(new UserHandle[]{MOCK_USER1, MOCK_USER2}, SYSTEM_PACKAGE2, SYSTEM_UID);
+        netdMonitor.expectPermission(SYSTEM, new UserHandle[]{MOCK_USER1, MOCK_USER2},
+                new int[]{SYSTEM_UID});
+
         addPackageForUsers(new UserHandle[]{MOCK_USER1, MOCK_USER2}, MOCK_PACKAGE1, MOCK_UID1);
         netdMonitor.expectPermission(SYSTEM, new UserHandle[]{MOCK_USER1, MOCK_USER2},
                 new int[]{SYSTEM_UID});
@@ -549,6 +564,10 @@
                 new int[]{MOCK_UID1});
 
         // Remove MOCK_UID1, expect no permission left for all user.
+        when(mPackageManager.getPackagesForUid(MOCK_USER1.getUid(MOCK_UID1)))
+                .thenReturn(new String[]{});
+        when(mPackageManager.getPackagesForUid(MOCK_USER2.getUid(MOCK_UID1)))
+                .thenReturn(new String[]{});
         mPermissionMonitor.onPackageRemoved(MOCK_PACKAGE1, MOCK_UID1);
         removePackageForUsers(new UserHandle[]{MOCK_USER1, MOCK_USER2}, MOCK_PACKAGE1, MOCK_UID1);
         netdMonitor.expectNoPermission(new UserHandle[]{MOCK_USER1, MOCK_USER2},