Intermittent issues with loginuid.so in Teleport 4.2.0

[russjones]

A customer has reported intermittent issues with loginuid.so on Ubuntu 16.04.6 running Teleport 4.2.0.

The issue occurs when upgrading Teleport nodes from 4.1.4 to 4.2.0 with loginuid.so set as required, only 2/5 logins succeed. On fresh installs (of Ubuntu as well as Teleport), login is always successful.

The errors look something like the following:

teleport: pam_loginuid(sshd:session): Error writing /proc/self/#uid: Operation not permitted
teleport: pam_loginuid(sshd:session): set_loginuid failed
teleport: pam_unix(sshd:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session closed for user root
teleport: pam_loginuid(sshd:session): Error writing /proc/self/#uid: Operation not permitted
teleport: pam_loginuid(sshd:session): set_loginuid failed
teleport: pam_unix(sshd:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session closed for user root
teleport: pam_unix(sshd:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session closed for user root
teleport: pam_unix(sshd:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
teleport: pam_loginuid(sshd:session): Error writing /proc/self/#uid: Operation not permitted
teleport: pam_loginuid(sshd:session): set_loginuid failed
teleport: pam_unix(sshd:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
systemd: pam_unix(systemd-user:session): session closed for user root

[russjones]

Closing in favor of #2476.