[RESTRICT AUTOMERGE] Trim the activity info of another uid if no privilege

The activity info could be from another uid which is different
from the app that hosts the task. The information should be
trimmed if the caller app doesn't have the privilege.

Bug: 243130512
Test: verified locally
Test: atest RecentTasksTest
Change-Id: Ia343ac70e5bb9aeae718fca6674e1ca491a14512
(cherry picked from commit 401e782b24)

services/core/java/com/android/server/wm/AppTaskImpl.java

@@ -84,7 +84,7 @@ class AppTaskImpl extends IAppTask.Stub {
                     throw new IllegalArgumentException("Unable to find task ID " + mTaskId);
                 }
                 return mService.getRecentTasks().createRecentTaskInfo(task,
-                        false /* stripExtras */);
+                        false /* stripExtras */, true /* getTasksAllowed */);
             } finally {
                 Binder.restoreCallingIdentity(origId);
             }

services/core/java/com/android/server/wm/RecentTasks.java

@@ -961,7 +961,7 @@ class RecentTasks {
                 continue;
             }
 
-            res.add(createRecentTaskInfo(task, true /* stripExtras */));
+            res.add(createRecentTaskInfo(task, true /* stripExtras */, getTasksAllowed));
         }
         return res;
     }
@@ -1833,12 +1833,16 @@ class RecentTasks {
     /**
      * Creates a new RecentTaskInfo from a Task.
      */
-    ActivityManager.RecentTaskInfo createRecentTaskInfo(Task tr, boolean stripExtras) {
+    ActivityManager.RecentTaskInfo createRecentTaskInfo(Task tr, boolean stripExtras,
+            boolean getTasksAllowed) {
         ActivityManager.RecentTaskInfo rti = new ActivityManager.RecentTaskInfo();
         tr.fillTaskInfo(rti, stripExtras);
         // Fill in some deprecated values
         rti.id = rti.isRunning ? rti.taskId : INVALID_TASK_ID;
         rti.persistentId = rti.taskId;
+        if (!getTasksAllowed) {
+            Task.trimIneffectiveInfo(tr, rti);
+        }
         return rti;
     }
 

services/core/java/com/android/server/wm/RunningTasks.java

@@ -129,6 +129,10 @@ class RunningTasks {
         final RunningTaskInfo rti = task.getTaskInfo();
         // Fill in some deprecated values
         rti.id = rti.taskId;
+
+        if (!mAllowed) {
+            Task.trimIneffectiveInfo(task, rti);
+        }
         return rti;
     }
 }

services/core/java/com/android/server/wm/Task.java

@@ -3631,6 +3631,27 @@ class Task extends WindowContainer<WindowContainer> {
                 : null;
     }
 
+    /**
+     * Removes the activity info if the activity belongs to a different uid, which is
+     * different from the app that hosts the task.
+     */
+    static void trimIneffectiveInfo(Task task, TaskInfo info) {
+        final ActivityRecord baseActivity = task.getActivity(r -> !r.finishing,
+                false /* traverseTopToBottom */);
+        final int baseActivityUid =
+                baseActivity != null ? baseActivity.getUid() : task.effectiveUid;
+
+        if (info.topActivityInfo != null
+                && task.effectiveUid != info.topActivityInfo.applicationInfo.uid) {
+            info.topActivity = null;
+            info.topActivityInfo = null;
+        }
+
+        if (task.effectiveUid != baseActivityUid) {
+            info.baseActivity = null;
+        }
+    }
+
     /**
      * Returns a {@link TaskInfo} with information from this task.
      */