From 5f6432b96a03a5503d3292d3654b3224d7f95596 Mon Sep 17 00:00:00 2001
From: Rhed Jao <rhedjao@google.com>
Date: Sat, 5 Jun 2021 12:27:41 +0800
Subject: [PATCH] Fix side channel leakage from the api of
 setInstallerPackageName

Enforce the package visibility filter on the argument of the
installer package name to fix the package information leakage
from the different exceptions thrown by the api.

Bug: 184851975
Test: atest AppEnumerationTests
Change-Id: I9fd36480fd0faaa954dc417992995dbbf5e68a2a
---
 .../java/com/android/server/pm/PackageManagerService.java  | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 00a68a08cb18d..80361e1688b41 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -16915,6 +16915,7 @@ public class PackageManagerService extends IPackageManager.Stub
     @Override
     public void setInstallerPackageName(String targetPackage, String installerPackageName) {
         final int callingUid = Binder.getCallingUid();
+        final int callingUserId = UserHandle.getUserId(callingUid);
         if (getInstantAppPackageName(callingUid) != null) {
             return;
         }
@@ -16923,14 +16924,16 @@ public class PackageManagerService extends IPackageManager.Stub
             PackageSetting targetPackageSetting = mSettings.getPackageLPr(targetPackage);
             if (targetPackageSetting == null
                     || shouldFilterApplicationLocked(
-                            targetPackageSetting, callingUid, UserHandle.getUserId(callingUid))) {
+                            targetPackageSetting, callingUid, callingUserId)) {
                 throw new IllegalArgumentException("Unknown target package: " + targetPackage);
             }
 
             PackageSetting installerPackageSetting;
             if (installerPackageName != null) {
                 installerPackageSetting = mSettings.getPackageLPr(installerPackageName);
-                if (installerPackageSetting == null) {
+                if (installerPackageSetting == null
+                        || shouldFilterApplicationLocked(
+                                installerPackageSetting, callingUid, callingUserId)) {
                     throw new IllegalArgumentException("Unknown installer package: "
                             + installerPackageName);
                 }