/etc/pam.d/runuser-l is in util-linux 2.25.2-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | #%PAM-1.0
auth include runuser
session optional pam_keyinit.so force revoke
-session optional pam_systemd.so
session include runuser
|