gnome-terminal drops pam_group config

[Philipp Takacs]

If you use pam_group to add users to a group and open gnome-terminal the dynamic group is lost.

How to reproduce:

enable pam_group
add "*;*;*;Al0000-2400;dialout" to /etc/security/group.conf
log in with a user which is not in the dialout group
open gnome-terminal
check with id if you in the dialout group

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-terminal 3.28.2-1ubuntu1~18.04.1
ProcVersionSignature: Ubuntu 4.15.0-54.58-generic 4.15.18
Uname: Linux 4.15.0-54-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
Date: Wed Jul 3 14:52:29 2019
SourcePackage: gnome-terminal
UpgradeStatus: No upgrade log present (probably fresh install)

[Egmont Koblinger (egmont-gmail)]

gnome-terminal itself doesn't do any authentication / PAM stuff. It's probably an issue with `systemd --user` which launches gnome-terminal.

[Philipp Takacs (ptakacs)]

I can start an other terminal (i.e. xterm) there are the groups correct. Starting a gnome-terminal from this terminal causes wrong groups in gnome-terminal. So either gnome-terminal sets the groups or uses a dbus/systemd/whatever funktion to set the groups. I would call both scenarios a bug in the gnome-terminal.

[Egmont Koblinger (egmont-gmail)]

> Starting a gnome-terminal from this terminal

Even executing "gnome-terminal" from an xterm goes through dbus/systemd. "gnome-terminal" is just a controlling client that asks systemd to start up a server which then displays the window and does all the rest.

Don't ask why the architecture is like this, I don't know. But gnome-terminal definitely doesn't do anything with groups, nor asks dbus/systemd/whatever to tamper with the groups.

The issue is probably in systemd, starting up gnome-terminal (and presumably any other app that it starts up) with the wrong groups.

[Philipp Takacs (ptakacs)]

I think you misunderstand me a bit.

> The issue is probably in systemd, starting up gnome-terminal (and
> presumably any other app that it starts up) with the wrong groups.

Yes gnome-terminal uses a systemd --user service to start a
terminal-server. This terminal-server is the parrent of all shells in
a gnome-terminal for this user.

The problem is systemd --user services are designed as per-user service
not per-session[0]. As I understand the Mailinglist, there ar no plans
to change this. So a systemd --user service isn't the right tool for
this architecture of a terminal and for any other programm which should
belong to a session. Thats why I say it's a bug in gnome-terminal not
in systemd.

That systemd has no per-session services is an other problem.

[0] https://lists.freedesktop.org/archives/systemd-devel/2014-March/017552.html

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.