[Samba] NT_STATUS_ACCESS_DENIED: Access denied (0xc0000022)

[Jeremy Allison]

On Fri, Sep 02, 2016 at 11:46:14AM -0400, Mark Foley via samba wrote:
> I have a Samba4 AD/DC running on Slackware64 14.1, Samba version 4.2.12. This computer has been
> serving a Domain of several Windows 7 and one Linux domain members for about 2 years without problem.
> 
> On a few occasions lately I've run the following command on the AD/DC:
> 
> $ ntlm_auth --username="user" --password='password'
> NT_STATUS_ACCESS_DENIED: Access denied (0xc0000022)
> 
> and have gotten the access denied message shown.  In other words, domain users suddenly can't
> authenticate.  Stopping and restarting samba does not fix the problem.  The samba log has:
> 
> [2016/09/02 11:19:36.490991,  2] ../libcli/auth/credentials.c:403(netlogon_creds_server_check_internal) credentials check failed
>   
> I have to reboot the computer to fix this.
> 
> It looks like my last update to Samba to 4.2.12 was done on July 2, 2016.  It's probable that I
> started noticing this problem about then.  It is very intermittant.  Probably less than 8
> times since then. 
> 
> Can anyone tell me why this is happening and how I can fix it without having to reboot?
> 
> This is important as this is a production machine and users are unable to log into the domain
> when this happens. 

Can you get logs showing what is going on when the machine is in
this state ? There's not enough information here to make a good
diagnosis.