From 3f14582b85d0ff363d21fba79e2cc99c6be25647 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 15 Aug 2022 14:05:54 +0200
Subject: [PATCH] LoginServer+LibCore: Only create user temp directory from
 LoginServer

Other programs use Core::Account::login(), notably su(1), which stopped
working due to a missing "cpath" pledge promise.

This patch moves the /tmp/user/ creation logic to a separate function
that LoginServer can call.
---
 Userland/Libraries/LibCore/Account.cpp | 15 +++++++--------
 Userland/Libraries/LibCore/Account.h   |  2 ++
 Userland/Services/LoginServer/main.cpp |  5 +++++
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/Userland/Libraries/LibCore/Account.cpp b/Userland/Libraries/LibCore/Account.cpp
index dc2e64a1d3..4135028211 100644
--- a/Userland/Libraries/LibCore/Account.cpp
+++ b/Userland/Libraries/LibCore/Account.cpp
@@ -149,17 +149,16 @@ bool Account::authenticate(SecretString const& password) const
     return hash != nullptr && AK::timing_safe_compare(hash, m_password_hash.characters(), m_password_hash.length());
 }
 
-bool Account::login() const
+ErrorOr<void> Account::create_user_temporary_directory_if_needed() const
 {
     auto const temporary_directory = String::formatted("/tmp/user/{}", m_uid);
-    if (auto result = Core::Directory::create(temporary_directory, Core::Directory::CreateDirectories::Yes); result.is_error()) {
-        dbgln("{}", result.release_error());
-        return false;
-    }
-
-    if (chown(temporary_directory.characters(), m_uid, m_gid) < 0)
-        return false;
+    TRY(Core::Directory::create(temporary_directory, Core::Directory::CreateDirectories::Yes));
+    TRY(Core::System::chown(temporary_directory, m_uid, m_gid));
+    return {};
+}
 
+bool Account::login() const
+{
     if (setgroups(m_extra_gids.size(), m_extra_gids.data()) < 0)
         return false;
 
diff --git a/Userland/Libraries/LibCore/Account.h b/Userland/Libraries/LibCore/Account.h
index 8e545aaad1..e75de6f71a 100644
--- a/Userland/Libraries/LibCore/Account.h
+++ b/Userland/Libraries/LibCore/Account.h
@@ -42,6 +42,8 @@ public:
     bool authenticate(SecretString const& password) const;
     bool login() const;
 
+    ErrorOr<void> create_user_temporary_directory_if_needed() const;
+
     String username() const { return m_username; }
     String password_hash() const { return m_password_hash; }
 
diff --git a/Userland/Services/LoginServer/main.cpp b/Userland/Services/LoginServer/main.cpp
index 8b539c9540..34fc819e2f 100644
--- a/Userland/Services/LoginServer/main.cpp
+++ b/Userland/Services/LoginServer/main.cpp
@@ -18,6 +18,11 @@
 
 static void child_process(Core::Account const& account)
 {
+    if (auto result = account.create_user_temporary_directory_if_needed(); result.is_error()) {
+        dbgln("Failed to create temporary directory for user {}: {}", account.username(), result.error());
+        exit(1);
+    }
+
     if (!account.login()) {
         dbgln("failed to switch users: {}", strerror(errno));
         exit(1);