/etc/pam.d/systemd-user is in systemd 237-3ubuntu10.
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 6 7 8 9 10 11 12 | # This file is part of systemd.
#
# Used by systemd --user instances.
@include common-account
session required pam_selinux.so close
session required pam_selinux.so nottys open
session required pam_loginuid.so
session required pam_limits.so
@include common-session-noninteractive
session optional pam_systemd.so
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