[Bug 1764853] Re: winbind returns PAM_AUTHINFO_UNAVAIL on first login after reboot

[msaxl]

I've tested if my suggested workaround would work. see ppa:saxl/ppa.

It works :)

Summary: Default 18.04 installation should not be affected since
/etc/hosts contains an entry with the local hostname. If ubuntu removes
this line by default the default installation will break (afaik systemd-
resolved should replace every /etc/hosts since it also resolves
localhost).

Technical problem: winbindd process must not use dbus with uid!=0.

My workaround makes sure it will not happen (in this case, kerberos
method = system keytab will still deadlock). The impact of this patch
should be zero since on a correctly configured system only uid==0 will
be able to use /etc/krb5.keytab so this workaround skips the step
loading the system keytab and failing doing so.

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https://bugs.launchpad.net/bugs/1764853

Title:
  winbind returns PAM_AUTHINFO_UNAVAIL on first login after reboot

Status in samba package in Ubuntu:
  Incomplete

Bug description:
  The following issue exists only on Ubuntu 18.04

  I've upgraded ubuntu from 17.10 and noticed that winbind does not work well.
  90% of the time I reboot my system I'm getting PAM_AUTHINFO_UNAVAIL when trying to log in with a domain account.
  clicking login again on the login screen most of the time succeeds (so the password is correct)

  I've checked if it works if I wait 10 minutes before logging in, no success, so it is not a timing issue.
  Also I've checked if winbind is working (log in with ssh using a local account)
  getent passwd xy and wbinfo -K user%pwd both work always.

  Now my workaround is putting
  winbind request timeout = 3
  in smb.conf, since the PAM_AUTHINFO_UNAVAIL is returned about 60sec after trying to login. This workaround solves nothing, it only makes logging in faster. (But now it fails mostly two times, but waiting 6 seconds is better than 60)

  To me it seems like deadlock, but I was unable to track it since it
  happens only on the first login. Then I would have to reboot
  (restarting winbind does not trigger it twice, also removing all
  caches in /run/samba does not trigger it twice)

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