Do not make ActivityContainer available to apps. DO NOT MERGE

A security leak was discovered whereby a malicious app could get the
IActivityContainer object from one app and use it to inject events
into another app. This fix removes the availability of the
IActivityContainer and replaces its one use with a method for
returning the information the IActivityContainer was used for.

Fixes bug 19394591.

Change-Id: Ib3cec25b25130cd8e098892c057742cfd575cfdd

4 files changed, 17 insertions, 32 deletions

diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index e8d08b8ccc2f..8c571692131f 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -17,7 +17,6 @@
 package android.app;
 
 import android.app.ActivityManager.StackInfo;
-import android.app.ProfilerInfo;
 import android.content.ComponentName;
 import android.content.IIntentReceiver;
 import android.content.IIntentSender;
@@ -2209,17 +2208,12 @@ public abstract class ActivityManagerNative extends Binder implements IActivityM
             return true;
         }
 
-        case GET_ACTIVITY_CONTAINER_TRANSACTION: {
+        case GET_ACTIVITY_DISPLAY_ID_TRANSACTION: {
             data.enforceInterface(IActivityManager.descriptor);
             IBinder activityToken = data.readStrongBinder();
-            IActivityContainer activityContainer = getEnclosingActivityContainer(activityToken);
+            int displayId = getActivityDisplayId(activityToken);
             reply.writeNoException();
-            if (activityContainer != null) {
-                reply.writeInt(1);
-                reply.writeStrongBinder(activityContainer.asBinder());
-            } else {
-                reply.writeInt(0);
-            }
+            reply.writeInt(displayId);
             return true;
         }
 
@@ -5238,26 +5232,21 @@ class ActivityManagerProxy implements IActivityManager
         reply.recycle();
     }
 
-    public IActivityContainer getEnclosingActivityContainer(IBinder activityToken)
-            throws RemoteException {
+    @Override
+    public int getActivityDisplayId(IBinder activityToken) throws RemoteException {
         Parcel data = Parcel.obtain();
         Parcel reply = Parcel.obtain();
         data.writeInterfaceToken(IActivityManager.descriptor);
         data.writeStrongBinder(activityToken);
-        mRemote.transact(GET_ACTIVITY_CONTAINER_TRANSACTION, data, reply, 0);
+        mRemote.transact(GET_ACTIVITY_DISPLAY_ID_TRANSACTION, data, reply, 0);
         reply.readException();
-        final int result = reply.readInt();
-        final IActivityContainer res;
-        if (result == 1) {
-            res = IActivityContainer.Stub.asInterface(reply.readStrongBinder());
-        } else {
-            res = null;
-        }
+        final int displayId = reply.readInt();
         data.recycle();
         reply.recycle();
-        return res;
+        return displayId;
     }
 
+    @Override
     public IBinder getHomeActivityToken() throws RemoteException {
         Parcel data = Parcel.obtain();
         Parcel reply = Parcel.obtain();
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index f2be45c463a8..8353d5472b8e 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -2339,10 +2339,7 @@ public final class ActivityThread {
 
         final DisplayManagerGlobal dm = DisplayManagerGlobal.getInstance();
         try {
-            IActivityContainer container =
-                    ActivityManagerNative.getDefault().getEnclosingActivityContainer(r.token);
-            final int displayId =
-                    container == null ? Display.DEFAULT_DISPLAY : container.getDisplayId();
+            final int displayId = ActivityManagerNative.getDefault().getActivityDisplayId(r.token);
             if (displayId > Display.DEFAULT_DISPLAY) {
                 Display display = dm.getRealDisplay(displayId, r.token);
                 baseContext = appContext.createDisplayContext(display);
diff --git a/core/java/android/app/IActivityManager.java b/core/java/android/app/IActivityManager.java
index e505d69078e5..dd3a38bf4e60 100644
--- a/core/java/android/app/IActivityManager.java
+++ b/core/java/android/app/IActivityManager.java
@@ -438,8 +438,7 @@ public interface IActivityManager extends IInterface {
 
     public void deleteActivityContainer(IActivityContainer container) throws RemoteException;
 
-    public IActivityContainer getEnclosingActivityContainer(IBinder activityToken)
-            throws RemoteException;
+    public int getActivityDisplayId(IBinder activityToken) throws RemoteException;
 
     public IBinder getHomeActivityToken() throws RemoteException;
 
@@ -754,7 +753,7 @@ public interface IActivityManager extends IInterface {
     int GET_PERSISTED_URI_PERMISSIONS_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+181;
     int APP_NOT_RESPONDING_VIA_PROVIDER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+182;
     int GET_HOME_ACTIVITY_TOKEN_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+183;
-    int GET_ACTIVITY_CONTAINER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+184;
+    int GET_ACTIVITY_DISPLAY_ID_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+184;
     int DELETE_ACTIVITY_CONTAINER_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+185;
 
 
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index e8f37572b079..2ab447ab4ec7 100755
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -57,6 +57,7 @@ import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.SparseIntArray;
 
+import android.view.Display;
 import com.android.internal.R;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.app.IAppOpsService;
@@ -8663,14 +8664,13 @@ public final class ActivityManagerService extends ActivityManagerNative
     }
 
     @Override
-    public IActivityContainer getEnclosingActivityContainer(IBinder activityToken)
-            throws RemoteException {
+    public int getActivityDisplayId(IBinder activityToken) throws RemoteException {
         synchronized (this) {
             ActivityStack stack = ActivityRecord.getStackLocked(activityToken);
-            if (stack != null) {
-                return stack.mActivityContainer;
+            if (stack != null && stack.mActivityContainer.isAttachedLocked()) {
+                return stack.mActivityContainer.getDisplayId();
             }
-            return null;
+            return Display.DEFAULT_DISPLAY;
         }
     }