pam_wheel 8 Linux-PAM Manual pam_wheel Only permit root access to members of group wheel pam_wheel.so debug deny group=name root_only trust use_uid 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. 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). use_uid The check for wheel membership will be done against the current uid instead of the original one (useful when jumping with su from one account to another for example). The auth and account module types are provided. 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. 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 pam.conf5 , pam.d5 , pam8 pam_wheel was written by Cristian Gafton <gafton@redhat.com>.