[Samba] winbind generates a UID for a group

[Anderson Sampaio Mello]

Hello samba team.

I have an AD DC server and winbind generates a UID for a group, for example
Domain Admins has its GID mapped to a SID and also a UID equal to the GID
mapped to the same SID.

I understand the mapping from GID to SID, but why does it generate a UID
for a group?

Example output of the wbinfo command:

wbinfo --group-info domain\\domain\ admins

Domain\domain admins:x:3000004:

wbinfo --user-info domain\\domain\ admins

Domain\domain admins:x:3000004:3000004::/home/Domain/domain
admins:/bin/false

The output of the commands: wbinfo --gid-to-sid and wbinfo --uid-to-sid
point to the SID of the domain admins group.

This happens with all domain and builtin groups as well.

The server has samba version 4.15.4 installed.