[Samba] Prevent `wbinfo -u` from making Winbind unresponsive

Alexey A Nikitin nikitin at amazon.com
Wed Apr 1 21:09:57 UTC 2020


Recently I by mistake ran `wbinfo -u <username>` when I was actually intending to run `wbinfo -n <username>`. It ignored the <username> part and proceeded to fetch the usernames. On a small domain this shouldn't be too much of an issue, but I did it on a domain with thousands upon thousands of users. The result was that Winbind became for all intents and purposes unresponsive for about six minutes - I couldn't authenticate me (or anyone else) for any new sessions, and it wouldn't even acknowledge me as a valid user in an existing session ('unknown uid: 3234505'). It pretty much blocked on that user search request for anything else, even things that were supposed to be cached locally like my UID.

I do have the following lines in smb.conf:

winbind enum users = no
winbind enum groups = no

Is there a way, preferrably without ugly hacks, to prevent this from happening on accident, by mistake? By this I mean ideally so that Winbind remains responsive even if someone mistakenly ran `wbinfo -u` or `wbinfo -g`, but limiting the result sets of these commands or blocking them altogether is acceptable too.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.samba.org/pipermail/samba/attachments/20200401/94f80d40/signature.sig>

More information about the samba mailing list