Logons very slow when using Winbind+AD group enumeration is configured and pam_listfile.so is used to allow only specific set of users and groups.

Issue

• The current version of pam_listfile is basically broken in modern environments, as it checks for group membership by enumerating the membership of every group on the system and looking to see if the given user is in it.

• That doesn't really scale in an enterprise environment with tens of thousands of groups.