From 7fdc96aef4e098d2271ac3a8557bd8e1ad6827f3 Mon Sep 17 00:00:00 2001 From: Oli Lan Date: Mon, 8 Aug 2022 13:31:36 +0100 Subject: RESTRICT AUTOMERGE Prevent non-admin users from deleting system apps. This addresses a security issue where the guest user can remove updates for system apps. With this CL, attempts to uninstall/downgrade system apps will fail if attempted by a non-admin user, unless the DELETE_SYSTEM_APP flag is specified. This is a fixed version of ag/17400663, to address b/236578018. Bug: 170646036 Test: manual, try uninstalling system app update as guest Change-Id: I5eab215cba6528aa4316ed7b20bee544915c1486 --- .../java/com/android/server/pm/PackageManagerService.java | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java index 789791d84b02..48b230d80a75 100644 --- a/services/core/java/com/android/server/pm/PackageManagerService.java +++ b/services/core/java/com/android/server/pm/PackageManagerService.java @@ -18687,6 +18687,17 @@ public class PackageManagerService extends IPackageManager.Stub return PackageManager.DELETE_FAILED_INTERNAL_ERROR; } + if (isSystemApp(uninstalledPs) + && (deleteFlags & PackageManager.DELETE_SYSTEM_APP) == 0) { + UserInfo userInfo = sUserManager.getUserInfo(userId); + if (userInfo == null || !userInfo.isAdmin()) { + Slog.w(TAG, "Not removing package " + packageName + + " as only admin user may downgrade system apps"); + EventLog.writeEvent(0x534e4554, "170646036", -1, packageName); + return PackageManager.DELETE_FAILED_USER_RESTRICTED; + } + } + disabledSystemPs = mSettings.getDisabledSystemPkgLPr(packageName); // Save the enabled state before we delete the package. When deleting a stub // application we always set the enabled state to 'disabled'. -- cgit v1.2.3-59-g8ed1b