From 8fd52796c41f85714a693b5462823004756aa8c9 Mon Sep 17 00:00:00 2001
From: Todd Kennedy <toddke@google.com>
Date: Wed, 10 Mar 2021 08:55:48 -0800
Subject: [PATCH] Null check before invoking callback

Also made sure to invoke the callback on the main
handler thread, like all other callbacks.

Fixes: 182164620
Test: atest PackageManagerTests
Change-Id: Ic2abe0877a716e83a10965bf348888a53ae95db8
---
 .../app/ApplicationPackageManager.java        | 19 ++++++++++---------
 .../content/pm/PackageManagerTests.java       |  9 ++++++++-
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/core/java/android/app/ApplicationPackageManager.java b/core/java/android/app/ApplicationPackageManager.java
index a6260d6d9cadd..dba62b9d3b63d 100644
--- a/core/java/android/app/ApplicationPackageManager.java
+++ b/core/java/android/app/ApplicationPackageManager.java
@@ -3228,6 +3228,12 @@ public class ApplicationPackageManager extends PackageManager {
     @Override
     public void registerDexModule(@NonNull String dexModule,
             @Nullable DexModuleRegisterCallback callback) {
+        // Create the callback delegate to be passed to package manager service.
+        DexModuleRegisterCallbackDelegate callbackDelegate = null;
+        if (callback != null) {
+            callbackDelegate = new DexModuleRegisterCallbackDelegate(callback);
+        }
+
         // Check if this is a shared module by looking if the others can read it.
         boolean isSharedModule = false;
         try {
@@ -3236,18 +3242,13 @@ public class ApplicationPackageManager extends PackageManager {
                 isSharedModule = true;
             }
         } catch (ErrnoException e) {
-            callback.onDexModuleRegistered(dexModule, false,
-                    "Could not get stat the module file: " + e.getMessage());
+            if (callbackDelegate != null) {
+                callback.onDexModuleRegistered(dexModule, false,
+                        "Could not get stat the module file: " + e.getMessage());
+            }
             return;
         }
 
-        // Module path is ok.
-        // Create the callback delegate to be passed to package manager service.
-        DexModuleRegisterCallbackDelegate callbackDelegate = null;
-        if (callback != null) {
-            callbackDelegate = new DexModuleRegisterCallbackDelegate(callback);
-        }
-
         // Invoke the package manager service.
         try {
             mPM.registerDexModule(mContext.getPackageName(), dexModule,
diff --git a/core/tests/coretests/src/android/content/pm/PackageManagerTests.java b/core/tests/coretests/src/android/content/pm/PackageManagerTests.java
index 57c0be5007b87..5d75d9b3f70b5 100644
--- a/core/tests/coretests/src/android/content/pm/PackageManagerTests.java
+++ b/core/tests/coretests/src/android/content/pm/PackageManagerTests.java
@@ -2923,7 +2923,7 @@ public class PackageManagerTests extends AndroidTestCase {
         assertFalse("BaseCodePath should not be registered", callback.mSuccess);
     }
 
-    // Verify thatmodules which are not own by the calling package are not registered.
+    // Verify that modules which are not own by the calling package are not registered.
     public void testRegisterDexModuleNotOwningModule() throws Exception {
         TestDexModuleRegisterCallback callback = new TestDexModuleRegisterCallback();
         String moduleBelongingToOtherPackage = "/data/user/0/com.google.android.gms/module.apk";
@@ -2978,6 +2978,13 @@ public class PackageManagerTests extends AndroidTestCase {
         assertFalse("DexModule registration should fail", callback.mSuccess);
     }
 
+    // If the module does not exist on disk we should get a failure.
+    public void testRegisterDexModuleNotExistsNoCallback() throws Exception {
+        ApplicationInfo info = getContext().getApplicationInfo();
+        String nonExistentApk = Paths.get(info.dataDir, "non-existent.apk").toString();
+        getPm().registerDexModule(nonExistentApk, null);
+    }
+
     // Copied from com.android.server.pm.InstructionSets because we don't have access to it here.
     private static String[] getAppDexInstructionSets(ApplicationInfo info) {
         if (info.primaryCpuAbi != null) {