DOKK / manpages / debian 10 / libpam-modules / pam_rootok.8.en
PAM_ROOTOK(8) Linux-PAM Manual PAM_ROOTOK(8)

pam_rootok - Gain only root access

pam_rootok.so [debug]

pam_rootok is a PAM module that authenticates the user if their UID is 0. Applications that are created setuid-root generally retain the UID of the user but run with the authority of an enhanced effective-UID. It is the real UID that is checked.

debug

Print debug information.

The auth, acct and password module types are provided.

PAM_SUCCESS

The UID is 0.

PAM_AUTH_ERR

The UID is not0.

In the case of the su(1) application the historical usage is to permit the superuser to adopt the identity of a lesser user without the use of a password. To obtain this behavior with PAM the following pair of lines are needed for the corresponding entry in the /etc/pam.d/su configuration file:

# su authentication. Root is granted access by default.
auth  sufficient   pam_rootok.so
auth  required     pam_unix.so

su(1), pam.conf(5), pam.d(5), pam(7)

pam_rootok was written by Andrew G. Morgan, <morgan@kernel.org>.

05/18/2017 Linux-PAM Manual