pam_wheel - Only permit root access to members of group wheel

       pam_wheel was written by Cristian Gafton <gafton@redhat.com>.

Linux-PAM                                          07/03/2025                                       PAM_WHEEL(8)

       The pam_wheel PAM module is used to enforce the so-called wheel group. By default it permits access to
       the target user if the applicant user is a member of the wheel group. If no group with this name exist,
       the module is using the group with the group-ID 0.

       The root account gains access by default (rootok), only wheel members can become root (wheel) but Unix
       authenticate non-root applicants.

           su      auth     sufficient     pam_rootok.so
           su      auth     required       pam_wheel.so
           su      auth     required       pam_unix.so

       The auth and account module types are provided.

       pam_wheel - Only permit root access to members of group wheel

       debug
           Print debug information.

       deny
           Reverse the sense of the auth operation: if the user is trying to get UID 0 access and is a member of
           the wheel group (or the group of the group option), deny access. Conversely, if the user is not in
           the group, return PAM_IGNORE (unless trust was also specified, in which case we return PAM_SUCCESS).

       group=name
           Instead of checking the wheel or GID 0 groups, use the name group to perform the authentication.

       root_only
           The check for wheel membership is done only when the target user UID is 0.

       trust
           The pam_wheel module will return PAM_SUCCESS instead of PAM_IGNORE if the user is a member of the
           wheel group (thus with a little play stacking the modules the wheel members may be able to su to root
           without being prompted for a passwd).

       PAM_AUTH_ERR
           Authentication failure.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_IGNORE
           The return value should be ignored by PAM dispatch.

       PAM_PERM_DENY
           Permission denied.

       PAM_SERVICE_ERR
           Cannot determine the user name.

       PAM_SUCCESS
           Success.

       PAM_USER_UNKNOWN
           User not known.

pam.conf(5), pam.d(5), pam(7)

pam_wheel.so [debug] [deny] [group=name] [root_only] [trust]