commit ee11625bb707c3512d4e44a35cc85b0bd14a2478
author lumark <lumark@google.com> Mon Feb 10 18:41:57 2020 +0800
committer Bryan Ferris <bferris@google.com> Wed Apr 29 18:07:04 2020 +0000
tree 42cca58300a678db9b0df4fffdd8e886c5865661
parent fee7e9913bf3e7e21b817dee93c24d9146202aca

[RESTRICT AUTOMERGE] Restrict app transition maximum duration

As WindowState#startAnimation for restricting window animation duration
(currently is 10 secs),

For security reason, we also need to restrict app transition animation
duration as 3 secs to prevent malicious app may set a long duration or
infinity repeat counts through ActivityOption#makeCustomAnimation or
Activity#overridePendingTransition with custom animation set.

Bug: 145728687
Test: manual as issue provided test app
Change-Id: I39051d6e4d2b681ce2becbafe14aab3f3d8ebf6b

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

diff --git a/services/core/java/com/android/server/wm/AppTransition.java b/services/core/java/com/android/server/wm/AppTransition.java
index d73606f..51b7279 100644
--- a/services/core/java/com/android/server/wm/AppTransition.java
+++ b/services/core/java/com/android/server/wm/AppTransition.java
@@ -161,6 +161,7 @@
     private static final int MAX_CLIP_REVEAL_TRANSITION_DURATION = 420;
     private static final int THUMBNAIL_APP_TRANSITION_DURATION = 336;
     private static final long APP_TRANSITION_TIMEOUT_MS = 5000;
+    static final int MAX_APP_TRANSITION_DURATION = 3 * 1000; // 3 secs.
 
     private final Context mContext;
     private final WindowManagerService mService;

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

diff --git a/services/core/java/com/android/server/wm/AppWindowToken.java b/services/core/java/com/android/server/wm/AppWindowToken.java
index bd5d35e..23af7d6 100644
--- a/services/core/java/com/android/server/wm/AppWindowToken.java
+++ b/services/core/java/com/android/server/wm/AppWindowToken.java
@@ -1843,7 +1843,16 @@
                 displayConfig.uiMode, displayConfig.orientation, frame, displayFrame, insets,
                 surfaceInsets, stableInsets, isVoiceInteraction, freeform, getTask().mTaskId);
         if (a != null) {
-            if (DEBUG_ANIM) logWithStack(TAG, "Loaded animation " + a + " for " + this);
+            if (a != null) {
+                // Setup the maximum app transition duration to prevent malicious app may set a long
+                // animation duration or infinite repeat counts for the app transition through
+                // ActivityOption#makeCustomAnimation or WindowManager#overridePendingTransition.
+                a.restrictDuration(MAX_APP_TRANSITION_DURATION);
+            }
+            if (DEBUG_ANIM) {
+                logWithStack(TAG, "Loaded animation " + a + " for " + this
+                        + ", duration: " + ((a != null) ? a.getDuration() : 0));
+            }
             final int containingWidth = frame.width();
             final int containingHeight = frame.height();
             a.initialize(containingWidth, containingHeight, width, height);