From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Daniel Norman <danielnorman@google.com>
Date: Thu, 9 Feb 2023 12:28:26 -0800
Subject: [PATCH] Checks if AccessibilityServiceInfo is within parcelable size.

- If too large when parsing service XMLs then skip this service.
- If too large when a service attempts to update its own info
  then throw an error.

Bug: 261589597
Test: atest AccessibilityServiceInfoTest
Change-Id: Iffc0cd48cc713f7904d68059e141cb7de5a4b906
Merged-In: Iffc0cd48cc713f7904d68059e141cb7de5a4b906
(cherry picked from commit on googleplex-android-review.googlesource.com host: 553232c29079fbeab28f95307d025c1426aa7142)
Merged-In: Iffc0cd48cc713f7904d68059e141cb7de5a4b906
---
 .../accessibilityservice/AccessibilityService.java     |  4 ++++
 .../accessibilityservice/AccessibilityServiceInfo.java | 10 ++++++++++
 .../accessibility/AccessibilityManagerService.java     |  6 ++++++
 3 files changed, 20 insertions(+)

diff --git a/core/java/android/accessibilityservice/AccessibilityService.java b/core/java/android/accessibilityservice/AccessibilityService.java
index b311c218de30..c0f6c3e5cb06 100644
--- a/core/java/android/accessibilityservice/AccessibilityService.java
+++ b/core/java/android/accessibilityservice/AccessibilityService.java
@@ -1400,6 +1400,10 @@ public abstract class AccessibilityService extends Service {
         IAccessibilityServiceConnection connection =
             AccessibilityInteractionClient.getInstance().getConnection(mConnectionId);
         if (mInfo != null && connection != null) {
+            if (!mInfo.isWithinParcelableSize()) {
+                throw new IllegalStateException(
+                        "Cannot update service info: size is larger than safe parcelable limits.");
+            }
             try {
                 connection.setServiceInfo(mInfo);
                 mInfo = null;
diff --git a/core/java/android/accessibilityservice/AccessibilityServiceInfo.java b/core/java/android/accessibilityservice/AccessibilityServiceInfo.java
index ee03280578e5..7be5eabc66c7 100644
--- a/core/java/android/accessibilityservice/AccessibilityServiceInfo.java
+++ b/core/java/android/accessibilityservice/AccessibilityServiceInfo.java
@@ -26,6 +26,7 @@ import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.content.res.XmlResourceParser;
 import android.os.Build;
+import android.os.IBinder;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.util.AttributeSet;
@@ -702,6 +703,15 @@ public class AccessibilityServiceInfo implements Parcelable {
         return 0;
     }
 
+    /** @hide */
+    public final boolean isWithinParcelableSize() {
+        final Parcel parcel = Parcel.obtain();
+        writeToParcel(parcel, 0);
+        final boolean result = parcel.dataSize() <= IBinder.MAX_IPC_SIZE;
+        parcel.recycle();
+        return result;
+    }
+
     public void writeToParcel(Parcel parcel, int flagz) {
         parcel.writeInt(eventTypes);
         parcel.writeStringArray(packageNames);
diff --git a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
index 718e30a43337..cae1adcafc23 100644
--- a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
+++ b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
@@ -1069,6 +1069,12 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
             AccessibilityServiceInfo accessibilityServiceInfo;
             try {
                 accessibilityServiceInfo = new AccessibilityServiceInfo(resolveInfo, mContext);
+                if (!accessibilityServiceInfo.isWithinParcelableSize()) {
+                    Slog.e(LOG_TAG, "Skipping service "
+                            + accessibilityServiceInfo.getResolveInfo().getComponentInfo()
+                            + " because service info size is larger than safe parcelable limits.");
+                    continue;
+                }
                 mTempAccessibilityServiceInfoList.add(accessibilityServiceInfo);
             } catch (XmlPullParserException | IOException xppe) {
                 Slog.e(LOG_TAG, "Error while initializing AccessibilityServiceInfo", xppe);