From 51d287d831364cb158330e132cd11b4c596c04c2 Mon Sep 17 00:00:00 2001 From: Jeff Chang Date: Tue, 25 Jan 2022 11:57:46 +0800 Subject: [PATCH] [RESTRICT AUTOMERGE] Do not resume activity if behind a translucent task The top-focusable activity resides in the RESUMED state while the app process is newly created and attached. The behavior may enable UI hijacking attacks against apps implementing authentication. This CL disallows the system to resume the activity for the case if it is not visible or is occluded by other translucent tasks. Bug: 211481342 Test: atest CtsWindowManagerDeviceTestCases:ActivityLifecycleTests Change-Id: I7903494cf928b5b5613700262b7c5fff10f3c5a0 --- .../server/wm/EnsureActivitiesVisibleHelper.java | 2 +- .../com/android/server/wm/RootWindowContainer.java | 3 ++- services/core/java/com/android/server/wm/Task.java | 11 +++++++++++ 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/services/core/java/com/android/server/wm/EnsureActivitiesVisibleHelper.java b/services/core/java/com/android/server/wm/EnsureActivitiesVisibleHelper.java index 316c20ba5c47f..e08816117f2ba 100644 --- a/services/core/java/com/android/server/wm/EnsureActivitiesVisibleHelper.java +++ b/services/core/java/com/android/server/wm/EnsureActivitiesVisibleHelper.java @@ -93,7 +93,7 @@ class EnsureActivitiesVisibleHelper { // activities are actually behind other fullscreen activities, but still required // to be visible (such as performing Recents animation). final boolean resumeTopActivity = mTop != null && !mTop.mLaunchTaskBehind - && mTask.isTopActivityFocusable() + && mTask.canBeResumed(starting) && (starting == null || !starting.isDescendantOf(mTask)); mTask.forAllActivities(a -> { diff --git a/services/core/java/com/android/server/wm/RootWindowContainer.java b/services/core/java/com/android/server/wm/RootWindowContainer.java index bd688a618c633..01c1989a80cbf 100644 --- a/services/core/java/com/android/server/wm/RootWindowContainer.java +++ b/services/core/java/com/android/server/wm/RootWindowContainer.java @@ -1948,7 +1948,8 @@ class RootWindowContainer extends WindowContainer try { if (mTaskSupervisor.realStartActivityLocked(r, app, - top == r && r.isFocusable() /*andResume*/, true /*checkConfig*/)) { + top == r && r.getTask().canBeResumed(r) /*andResume*/, + true /*checkConfig*/)) { mTmpBoolean = true; } } catch (RemoteException e) { diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java index c0e339f8a6b73..2e641717cb7f2 100644 --- a/services/core/java/com/android/server/wm/Task.java +++ b/services/core/java/com/android/server/wm/Task.java @@ -4240,6 +4240,17 @@ class Task extends WindowContainer { return getVisibility(starting) != TASK_VISIBILITY_INVISIBLE; } + /** + * Returns {@code true} is the activity in this Task can be resumed. + * + * @param starting The currently starting activity or {@code null} if there is none. + */ + boolean canBeResumed(@Nullable ActivityRecord starting) { + // No need to resume activity in Task that is not visible. + return isTopActivityFocusable() + && getVisibility(starting) == TASK_VISIBILITY_VISIBLE; + } + /** * Returns true if the task should be visible. *