DivestOS/Patches/LineageOS-21.0/android_frameworks_base/0029-Strict_Package_Checks-4.patch

From 66d463347a80617e13f5c5f26b4be07380421876 Mon Sep 17 00:00:00 2001
From: Dmitry Muhomor <muhomor.dmitry@gmail.com>
Date: Tue, 27 Dec 2022 11:40:14 +0200
Subject: [PATCH] don't allow updating system packages to the same versionCode

versionCode of many system packages, including privileged ones, is set to the current SDK version
and is thus not incremented during non-major OS upgrades.
This allowed to downgrade them to the older version that had the same versionCode.
---
 .../android/server/pm/InstallPackageHelper.java | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/pm/InstallPackageHelper.java b/services/core/java/com/android/server/pm/InstallPackageHelper.java
index 4d58218b0cc7..71abd7fd1f89 100644
--- a/services/core/java/com/android/server/pm/InstallPackageHelper.java
+++ b/services/core/java/com/android/server/pm/InstallPackageHelper.java
@@ -1624,7 +1624,22 @@ && cannotInstallWithBadPermissionGroups(parsedPackage)) {
                 }
 
                 if (abortInstall) {
-                    throw new PrepareFailure(INSTALL_FAILED_INTERNAL_ERROR, message);
+                    throw new PrepareFailure(PackageManager.INSTALL_FAILED_INTERNAL_ERROR, message);
+                }
+            }
+
+            if (parsedPackage.getLongVersionCode() == systemPackage.getLongVersionCode()) {
+                String message = "Not allowed to update system package to the same versionCode";
+                boolean abortInstall = true;
+
+                if (Build.IS_DEBUGGABLE) {
+                    if (SystemProperties.getBoolean("persist.disable_same_versionCode_sys_pkg_update_check", false)) {
+                        Slog.d(TAG, message + ": " + parsedPackage.getManifestPackageName());
+                        abortInstall = false;
+                    }
+                }
+                if (abortInstall) {
+                    throw new PrepareFailure(PackageManager.INSTALL_FAILED_INTERNAL_ERROR, message);
                 }
             }
         }