[SSSD-users] SSH user fails system error 4

[Sangster, Mark]

Hello,

We are experiencing an issue with a user when they attempt to login. Other users can
continue to login. It does seem to repeat on this specific user.

If I blitz the SSSD cache and restart it, then they find they can login again.

They indicated that just prior to the event, they were forced to reboot their machine
(i.e. unclean disconnect) and it was after that they couldn’t login.

This was the successful session just before:

Jun 17 08:00:58 server sshd[11882]: pam_sss(sshd:auth): authentication success; logname=
uid=0 euid=0 tty=ssh ruser= rhost=<CLIENTIP> user=username
Jun 17 08:00:58 server sshd[11882]: Accepted password for username from <CLIENTIP>
port 59680 ssh2
Jun 17 08:00:59 server sshd[11882]: pam_unix(sshd:session): session opened for user
username by (uid=0)
Jun 17 13:22:17 server sshd[11882]: pam_unix(sshd:session): session closed for user
username

The next session which failed:

Jun 17 13:33:13 server sshd[13210]: pam_sss(sshd:auth): authentication success; logname=
uid=0 euid=0 tty=ssh ruser= rhost=<CLIENTIP> user=username
Jun 17 13:33:13 server sshd[13210]: pam_sss(sshd:account): Access denied for user
username: 4 (System error)
Jun 17 13:33:13 server sshd[13210]: Failed password for username from <CLIENTIP>
port 50114 ssh2
Jun 17 13:33:13 server sshd[13210]: fatal: Access denied for user username by PAM account
configuration [preauth]

There does not look to be any additional log information in SSSD representing the error.
The troubleshooting suggested I follow up here for “system error 4”.

It would be tricky to run debug on this, as this took 4 days until the failure reappeared
and we might fill our log space very quickly.

Thanks
Mark

------------------------------------------------------------------------
Mark Sangster
Server Infrastructure Specialist

Information Technology Services | University of Aberdeen
t: [phone] | e: [e-mail]<mailto:[e-mail]> | u:
http://www.abdn.ac.uk/it/



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