[Samba] Standalone Update 4.8.5 -> 4.9.2 smb fails to start ERROR: failed to setup guest info.

[David C. Rankin]

Samba Devs,

  Very strange error - smb fails to start on Archlinux after upgrade from
4.8.5 -> 4.9.2 on a simple standalone server. This server has run for years
just fine through all upgrades, but on this one, smb cannot start:

# sc -l --no-pager status smb
● smb.service - Samba SMB Daemon
   Loaded: loaded (/usr/lib/systemd/system/smb.service; enabled; vendor
preset: disabled)
   Active: failed (Result: exit-code) since Wed 2018-11-21 17:59:29 CST; 3s ago
     Docs: man:smbd(8)
           man:samba(7)
           man:smb.conf(5)
  Process: 10684 ExecStart=/usr/bin/smbd --foreground --no-process-group
$SMBDOPTIONS (code=exited, status=255)
 Main PID: 10684 (code=exited, status=255)

Nov 21 17:59:29 phoinix systemd[1]: Starting Samba SMB Daemon...
Nov 21 17:59:29 phoinix smbd[10684]: [2018/11/21 17:59:29.478644,  0]
../source3/auth/auth_util.c:1382(make_new_session_info_guest)
Nov 21 17:59:29 phoinix smbd[10684]:   create_local_token failed:
NT_STATUS_ACCESS_DENIED
Nov 21 17:59:29 phoinix smbd[10684]: [2018/11/21 17:59:29.478734,  0]
../source3/smbd/server.c:2000(main)
Nov 21 17:59:29 phoinix smbd[10684]:   ERROR: failed to setup guest info.
Nov 21 17:59:29 phoinix systemd[1]: smb.service: Main process exited,
code=exited, status=255/n/a
Nov 21 17:59:29 phoinix systemd[1]: smb.service: Failed with result 'exit-code'.
Nov 21 17:59:29 phoinix systemd[1]: Failed to start Samba SMB Daemon.

  Downgrading to 4.8.5 and all is fine. The config (testparm output) is:

# testparm
Load smb config files from /etc/samba/smb.conf
rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
Processing section "[homes]"
Processing section "[config]"
Processing section "[http]"
Processing section "[samba]"
Processing section "[printers]"
Processing section "[print$]"
Processing section "[pdf-gen]"
Loaded services file OK.
Server role: ROLE_STANDALONE

Press enter to see a dump of your service definitions

# Global parameters
[global]
        dns proxy = No
        domain master = Yes
        log file = /var/log/samba/client-%m.log
        max log size = 500
        os level = 66
        preferred master = Yes
        printcap name = /etc/printcap
        security = USER
        server string = Phoinix Samba %v
        show add printer wizard = No
        smb passwd file = /etc/samba/smbpasswd
        time server = Yes
        wins support = Yes
        workgroup = RLFPLLC
        idmap config * : backend = tdb
        admin users = david
        hosts allow = 192.168.6. 192.168.7. 127.

[homes]
        browseable = No
        comment = Home Directories
        read only = No
...
[printers]
        browseable = No
        comment = All Printers
        create mask = 0700
        guest ok = Yes
        path = /var/spool/samba
        printable = Yes
        use client driver = Yes


  The only place 'guest' is used is in the [printers] share with "guest ok =
Yes". I'm at a loss what the following is trying to tell me:

    ../source3/auth/auth_util.c:1382(make_new_session_info_guest)
    create_local_token failed: NT_STATUS_ACCESS_DENIED
    ../source3/smbd/server.c:2000(main)
    ERROR: failed to setup guest info.

It doesn't tell me a whole lot other than something went South regarding
"guest info"? Why this is different in 4.9.2 from 4.8.5, I haven't a clue, but
4.8.5 works just fine. I have several other samba boxes with very similar
configs (other than they are not the browse master or win server or time server)

  I've googled and found nothing related to 4.8 - 4.9 updates regarding this
error, or I just wasn't smart enough to find it. The bewildering part is I
have 2 other Arch servers with practically identical configs and they handled
the update just fine - so I'm not sure where to go from here. The only
difference between the boxes is that this one has probably been in service the
longest, going back to at least samba 4.1 -- if that makes any difference.

  What to check?

-- 
David C. Rankin, J.D.,P.E.