[Samba] No Domain Logon Possible after last Windows 11 Insider Update

[Adam Thorn]

On 18/01/2022 10:08, Dirk Laurenz via samba wrote:
> Hello everyone,
> 
>   
> 
> i updated my windows 11 Insider to the latest build and afterwards is no
> domain logon is possible.
> 
> I restored to the old state - and logons are possible - updated again - and
> no logon possible

This might be unrelated to your problem, but in case anyone else is 
caught out by this ....

We have a custom usermap script in place due to our local setup (not 
specifically due to some of the recent CVEs and subsequent fallout). We 
do some parsing of the "DOMAIN+username" string passed to the script, 
where DOMAIN is the upper-case version of our domain name.

We've had reports of behaviour where the latest Windows 11 build (sorry, 
I don't know the build number) seems to forcibly lower-case (part or all 
of?) saved credentials and a user then ends up trying to authenticate to 
a share as "domain+user" rather than "DOMAIN+user", which we hadn't 
properly handled in our usermap script. The user affected by this 
reports they were able to successfully make their Win 11 client forget 
any saved credentials and then re-save the original "DOMAIN+user" 
version, after which they could connect to shares again.

Even if you don't have a usermap script in place, it might be worth 
looking to see if you'd be affected by an unexpected/unhandled change in 
the case of the domain name anywhere.

Regards,

Adam