This bug was initially created as a copy of Bug #1861836 I am copying this bug because: The same issue is present on RHEL9 Description of problem: When polyinstantiation is enabled and a user logs in via GDM, applications that are started via systemd (e.g. gnome-terminal) do not run in the same namespace of gnome-shell and therefore bypass the polyinstantiation. Version-Release number of selected component (if applicable): - gdm-3.28.3-29.el8.x86_64 - gnome-shell-3.32.2-14.el8.x86_64 - pam-1.3.1-8.el8.x86_64 - selinux-policy-3.14.3-41.el8_2.5.noarch - gnome-session-3.28.1-8.el8.x86_64 - gnome-session-wayland-session-3.28.1-8.el8.x86_64 - gnome-session-xsession-3.28.1-8.el8.x86_64 How reproducible: Always Steps to Reproduce: 1. Enable Wayland in /etc/gdm/custom.conf; optionally log in choosing a "X11 display server" session, in step 6. 2. Ensure that /etc/pam.d/gdm-* use pam_namespace.so session required pam_namespace.so 3. Enable polyinstantiation of /tmp and $HOME in /etc/security/namespace.conf $HOME $HOME/$USER.inst/ level 4. If SELinux is in use, enable polyinstantiation # setsebool -P allow_polyinstantiation 1 5. Restart gdm # systemctl restart gdm.service 6. Try to log in as an ordinary user. If Wayland was not disabled in step 1, log in choosing a "X11 display server" session. 7. Open a gnome-terminal window and run $ ps -eo pid,user,mntns,command --sort mntns | fgrep " $(id -nu) " | fgrep -e gnome-terminal-server -e gnome-session-binary -e 'systemd --user' Actual results: The namespace inode numbers of gnome-session-binary and gnome-terminal-server are not the same. Example: 106296 casantos 4026531840 /usr/lib/systemd/systemd --user 106979 casantos 4026531840 /usr/libexec/gnome-terminal-server 106375 casantos 4026532604 /usr/libexec/gnome-session-binary Expected results: The namespace inode numbers of gnome-session-binary and gnome-terminal-server should be the same. Example: 108479 casantos 4026531840 /usr/lib/systemd/systemd --user 108559 casantos 4026532604 /usr/libexec/gnome-session-binary 109178 casantos 4026532604 /usr/libexec/gnome-terminal-server Since the processes started by systemd --user do dot run in the same namespace of gnome-session-binary, the polyinstantiation of $HOME does not have effect. Additional info: The problem can be circumvented by adding a session init script that updates the DBUS_SESSION_BUS_ADDRESS and DBUS_SESSION_BUS_PID environment variables. Example: # cat /etc/X11/xinit/xinitrc.d/99-override-message-bus.sh eval $(dbus-launch --sh-syntax --exit-with-session)