From 163cb98751fa523ecd9bd9388fd86d477a13698d Mon Sep 17 00:00:00 2001
From: Junyu Lai <junyulai@google.com>
Date: Fri, 16 Sep 2022 10:40:48 +0800
Subject: [PATCH] Partially enforce permission when calling
 getNetworkInfoForUid

Test: atest ConnectivityServiceTest#testGetNetworkInfoForUid
Change-Id: Ie0ac289e77a865cf3cc98a6a2bbd5b25cf402622
---
 .../android/server/ConnectivityService.java   |  3 ++
 .../server/ConnectivityServiceTest.java       | 47 +++++++++++++++++--
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 93265e51ca..db0e9e521f 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -1976,6 +1976,9 @@ public class ConnectivityService extends IConnectivityManager.Stub
     @Nullable
     public NetworkInfo getNetworkInfoForUid(Network network, int uid, boolean ignoreBlocked) {
         enforceAccessPermission();
+        if (uid != mDeps.getCallingUid()) {
+            enforceNetworkStackPermission(mContext);
+        }
         final NetworkAgentInfo nai = getNetworkAgentInfoForNetwork(network);
         if (nai == null) return null;
         return getFilteredNetworkInfo(nai, uid, ignoreBlocked);
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index d2a71354ec..61ba144d1a 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -1603,9 +1603,9 @@ public class ConnectivityServiceTest {
         mMockVpn = new MockVpn(userId);
     }
 
-    private void mockUidNetworkingBlocked() {
+    private void mockUidNetworkingBlocked(int uid) {
         doAnswer(i -> isUidBlocked(mBlockedReasons, i.getArgument(1))
-        ).when(mNetworkPolicyManager).isUidNetworkingBlocked(anyInt(), anyBoolean());
+        ).when(mNetworkPolicyManager).isUidNetworkingBlocked(eq(uid), anyBoolean());
     }
 
     private boolean isUidBlocked(int blockedReasons, boolean meteredNetwork) {
@@ -8903,7 +8903,7 @@ public class ConnectivityServiceTest {
         final DetailedBlockedStatusCallback detailedCallback = new DetailedBlockedStatusCallback();
         mCm.registerNetworkCallback(cellRequest, detailedCallback);
 
-        mockUidNetworkingBlocked();
+        mockUidNetworkingBlocked(Process.myUid());
 
         mCellNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
         mCellNetworkAgent.connect(true);
@@ -9018,7 +9018,7 @@ public class ConnectivityServiceTest {
     public void testNetworkBlockedStatusBeforeAndAfterConnect() throws Exception {
         final TestNetworkCallback defaultCallback = new TestNetworkCallback();
         mCm.registerDefaultNetworkCallback(defaultCallback);
-        mockUidNetworkingBlocked();
+        mockUidNetworkingBlocked(Process.myUid());
 
         // No Networkcallbacks invoked before any network is active.
         setBlockedReasonChanged(BLOCKED_REASON_BATTERY_SAVER);
@@ -16781,4 +16781,43 @@ public class ConnectivityServiceTest {
             verify(mTetheringManager).getTetherableWifiRegexs();
         });
     }
+
+    @Test
+    public void testGetNetworkInfoForUid() throws Exception {
+        // Setup and verify getNetworkInfoForUid cannot be called without Network Stack permission,
+        // when querying NetworkInfo for other uid.
+        verifyNoNetwork();
+        mWiFiNetworkAgent = new TestNetworkAgentWrapper(TRANSPORT_WIFI);
+        mServiceContext.setPermission(NETWORK_STACK, PERMISSION_DENIED);
+        mServiceContext.setPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
+                PERMISSION_DENIED);
+
+        final int otherUid = Process.myUid() + 1;
+        assertNull(mCm.getActiveNetwork());
+        assertNull(mCm.getNetworkInfoForUid(mCm.getActiveNetwork(),
+                Process.myUid(), false /* ignoreBlocked */));
+        assertThrows(SecurityException.class, () -> mCm.getNetworkInfoForUid(
+                mCm.getActiveNetwork(), otherUid, false /* ignoreBlocked */));
+        withPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, () ->
+                assertNull(mCm.getNetworkInfoForUid(mCm.getActiveNetwork(),
+                        otherUid, false /* ignoreBlocked */)));
+
+        // Bringing up validated wifi and verify again. Make the other uid be blocked,
+        // verify the method returns result accordingly.
+        mWiFiNetworkAgent.connect(true);
+        setBlockedReasonChanged(BLOCKED_REASON_BATTERY_SAVER);
+        mockUidNetworkingBlocked(otherUid);
+        withPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, () ->
+                verifyActiveNetwork(TRANSPORT_WIFI));
+        checkNetworkInfo(mCm.getNetworkInfoForUid(mCm.getActiveNetwork(),
+                Process.myUid(), false /* ignoreBlocked */), TYPE_WIFI, DetailedState.CONNECTED);
+        assertThrows(SecurityException.class, () -> mCm.getNetworkInfoForUid(
+                mCm.getActiveNetwork(), otherUid, false /* ignoreBlocked */));
+        withPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, () ->
+                checkNetworkInfo(mCm.getNetworkInfoForUid(mCm.getActiveNetwork(),
+                        otherUid, false /* ignoreBlocked */), TYPE_WIFI, DetailedState.BLOCKED));
+        withPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, () ->
+                checkNetworkInfo(mCm.getNetworkInfoForUid(mCm.getActiveNetwork(),
+                        otherUid, true /* ignoreBlocked */), TYPE_WIFI, DetailedState.CONNECTED));
+    }
 }