Make sure that only the owner can call stopVpnProfile()

In stopVpnProfile(), it doesn't check if the caller's package
name is the same as the given one, so any app has chance to stop
the VPN profile of other apps.

Bug: 191382886
Test: atest FrameworksNetTests CtsNetTestCases \
      CtsHostsideNetworkTests:HostsideVpnTests
Change-Id: Ib0a6e9ed191ff8c8bd55ce9902d894b6a339ace2
Merged-In: I254ffd1c08ec058d594b4ea55cbae5505f8497cc
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index fcf73ac..0eab71a 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -73,6 +73,7 @@
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.res.Configuration;
 import android.database.ContentObserver;
 import android.net.CaptivePortal;
@@ -4607,6 +4608,25 @@
         }
     }
 
+    private int getAppUid(final String app, final int userId) {
+        final PackageManager pm = mContext.getPackageManager();
+        final long token = Binder.clearCallingIdentity();
+        try {
+            return pm.getPackageUidAsUser(app, userId);
+        } catch (NameNotFoundException e) {
+            return -1;
+        } finally {
+            Binder.restoreCallingIdentity(token);
+        }
+    }
+
+    private void verifyCallingUidAndPackage(String packageName, int callingUid) {
+        final int userId = UserHandle.getUserId(callingUid);
+        if (getAppUid(packageName, userId) != callingUid) {
+            throw new SecurityException(packageName + " does not belong to uid " + callingUid);
+        }
+    }
+
     /**
      * Starts the VPN based on the stored profile for the given package
      *
@@ -4618,7 +4638,9 @@
      */
     @Override
     public void startVpnProfile(@NonNull String packageName) {
-        final int user = UserHandle.getUserId(Binder.getCallingUid());
+        final int callingUid = Binder.getCallingUid();
+        verifyCallingUidAndPackage(packageName, callingUid);
+        final int user = UserHandle.getUserId(callingUid);
         synchronized (mVpns) {
             throwIfLockdownEnabled();
             mVpns.get(user).startVpnProfile(packageName, mKeyStore);
@@ -4635,7 +4657,9 @@
      */
     @Override
     public void stopVpnProfile(@NonNull String packageName) {
-        final int user = UserHandle.getUserId(Binder.getCallingUid());
+        final int callingUid = Binder.getCallingUid();
+        verifyCallingUidAndPackage(packageName, callingUid);
+        final int user = UserHandle.getUserId(callingUid);
         synchronized (mVpns) {
             mVpns.get(user).stopVpnProfile(packageName);
         }
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index a5554c7..e9301d1 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -1224,6 +1224,9 @@
                 Arrays.asList(new UserInfo[] {
                         new UserInfo(VPN_USER, "", 0),
                 }));
+        final int userId = UserHandle.getCallingUserId();
+        final UserInfo primaryUser = new UserInfo(userId, "", UserInfo.FLAG_PRIMARY);
+        doReturn(primaryUser).when(mUserManager).getUserInfo(eq(userId));
         final ApplicationInfo applicationInfo = new ApplicationInfo();
         applicationInfo.targetSdkVersion = Build.VERSION_CODES.Q;
         when(mPackageManager.getApplicationInfoAsUser(anyString(), anyInt(), any()))
@@ -1368,6 +1371,9 @@
                         buildPackageInfo(/* SYSTEM */ false, APP2_UID),
                         buildPackageInfo(/* SYSTEM */ false, VPN_UID)
                 }));
+        final int userId = UserHandle.getCallingUserId();
+        when(mPackageManager.getPackageUidAsUser(TEST_PACKAGE_NAME, userId))
+                .thenReturn(Process.myUid());
     }
 
     private void verifyActiveNetwork(int transport) {
@@ -7069,6 +7075,18 @@
     }
 
     @Test
+    public void testStartVpnProfileFromDiffPackage() throws Exception {
+        final String notMyVpnPkg = "com.not.my.vpn";
+        assertThrows(SecurityException.class, () -> mService.startVpnProfile(notMyVpnPkg));
+    }
+
+    @Test
+    public void testStopVpnProfileFromDiffPackage() throws Exception {
+        final String notMyVpnPkg = "com.not.my.vpn";
+        assertThrows(SecurityException.class, () -> mService.stopVpnProfile(notMyVpnPkg));
+    }
+
+    @Test
     public void testUidUpdateChangesInterfaceFilteringRule() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("tun0");