From 038a19ba97a7bce6e40597cbff70a2e22c3d3c13 Mon Sep 17 00:00:00 2001
From: Alex Buynytskyy <alexbuy@google.com>
Date: Wed, 9 Feb 2022 19:51:52 -0800
Subject: More robust app data and user data removal.

1. rename the folder, so any new files will end up in the renamed
   folder.
   this also greatly reduces chances that app will be able to create new files.
2. delete the renamed folder
3. provide an api to cleanup renamed/deleted folders on system startup

Bug: 162757029
Test: atest installd_service_test installd_cache_test installd_utils_test installd_dexopt_test installd_otapreopt_test installd_file_test
Change-Id: If1c209d49675f7fa9df60b6136588e3b0a7786e5
---
 cmds/installd/InstalldNativeService.cpp | 34 ++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

(limited to 'cmds/installd/InstalldNativeService.cpp')

diff --git a/cmds/installd/InstalldNativeService.cpp b/cmds/installd/InstalldNativeService.cpp
index c3256fcfff..89d4868b09 100644
--- a/cmds/installd/InstalldNativeService.cpp
+++ b/cmds/installd/InstalldNativeService.cpp
@@ -968,13 +968,13 @@ binder::Status InstalldNativeService::destroyAppData(const std::optional<std::st
     binder::Status res = ok();
     if (flags & FLAG_STORAGE_CE) {
         auto path = create_data_user_ce_package_path(uuid_, userId, pkgname, ceDataInode);
-        if (delete_dir_contents_and_dir(path) != 0) {
+        if (rename_delete_dir_contents_and_dir(path) != 0) {
             res = error("Failed to delete " + path);
         }
     }
     if (flags & FLAG_STORAGE_DE) {
         auto path = create_data_user_de_package_path(uuid_, userId, pkgname);
-        if (delete_dir_contents_and_dir(path) != 0) {
+        if (rename_delete_dir_contents_and_dir(path) != 0) {
             res = error("Failed to delete " + path);
         }
         if ((flags & FLAG_CLEAR_APP_DATA_KEEP_ART_PROFILES) == 0) {
@@ -1005,16 +1005,15 @@ binder::Status InstalldNativeService::destroyAppData(const std::optional<std::st
             }
 
             auto path = StringPrintf("%s/Android/data/%s", extPath.c_str(), pkgname);
-            if (delete_dir_contents_and_dir(path, true) != 0) {
+            if (rename_delete_dir_contents_and_dir(path, true) != 0) {
                 res = error("Failed to delete contents of " + path);
             }
-
             path = StringPrintf("%s/Android/media/%s", extPath.c_str(), pkgname);
-            if (delete_dir_contents_and_dir(path, true) != 0) {
+            if (rename_delete_dir_contents_and_dir(path, true) != 0) {
                 res = error("Failed to delete contents of " + path);
             }
             path = StringPrintf("%s/Android/obb/%s", extPath.c_str(), pkgname);
-            if (delete_dir_contents_and_dir(path, true) != 0) {
+            if (rename_delete_dir_contents_and_dir(path, true) != 0) {
                 res = error("Failed to delete contents of " + path);
             }
         }
@@ -1562,27 +1561,27 @@ binder::Status InstalldNativeService::destroyUserData(const std::optional<std::s
     binder::Status res = ok();
     if (flags & FLAG_STORAGE_DE) {
         auto path = create_data_user_de_path(uuid_, userId);
-        if (delete_dir_contents_and_dir(path, true) != 0) {
+        if (rename_delete_dir_contents_and_dir(path, true) != 0) {
             res = error("Failed to delete " + path);
         }
         if (uuid_ == nullptr) {
             path = create_data_misc_legacy_path(userId);
-            if (delete_dir_contents_and_dir(path, true) != 0) {
+            if (rename_delete_dir_contents_and_dir(path, true) != 0) {
                 res = error("Failed to delete " + path);
             }
             path = create_primary_cur_profile_dir_path(userId);
-            if (delete_dir_contents_and_dir(path, true) != 0) {
+            if (rename_delete_dir_contents_and_dir(path, true) != 0) {
                 res = error("Failed to delete " + path);
             }
         }
     }
     if (flags & FLAG_STORAGE_CE) {
         auto path = create_data_user_ce_path(uuid_, userId);
-        if (delete_dir_contents_and_dir(path, true) != 0) {
+        if (rename_delete_dir_contents_and_dir(path, true) != 0) {
             res = error("Failed to delete " + path);
         }
         path = findDataMediaPath(uuid, userId);
-        if (delete_dir_contents_and_dir(path, true) != 0) {
+        if (rename_delete_dir_contents_and_dir(path, true) != 0) {
             res = error("Failed to delete " + path);
         }
     }
@@ -3324,5 +3323,18 @@ binder::Status InstalldNativeService::migrateLegacyObbData() {
     return ok();
 }
 
+binder::Status InstalldNativeService::cleanupDeletedDirs(const std::optional<std::string>& uuid) {
+    const char* uuid_cstr = uuid ? uuid->c_str() : nullptr;
+    const auto users = get_known_users(uuid_cstr);
+    for (auto userId : users) {
+        auto ce_path = create_data_user_ce_path(uuid_cstr, userId);
+        auto de_path = create_data_user_de_path(uuid_cstr, userId);
+
+        find_and_delete_renamed_deleted_dirs_under_path(ce_path);
+        find_and_delete_renamed_deleted_dirs_under_path(de_path);
+    }
+    return ok();
+}
+
 }  // namespace installd
 }  // namespace android
-- 
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