Man page 8 : pam_wheel

pam_wheel - Only permit root access to members of group wheel

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

The pam_wheel PAM module is used to enforce the so-called wheel group. By default it permits root access to the system 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=\fBname\fR
    Instead of checking the wheel or GID 0 groups, use the \fBname\fR group to perform the authentication.

root_only
    The check for wheel membership is done only.

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).

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

pam_wheel was written by Cristian Gafton <>.