以下为CentOS Linux release 8.5.2111系统/etc/pam.d/su默认配置。

[root@localhost authselect]# cat /etc/pam.d/su
#%PAM-1.0
auth            required        pam_env.so
auth            sufficient      pam_rootok.so
# Uncomment the following line to implicitly trust users in the "wheel" group.
#auth           sufficient      pam_wheel.so trust use_uid
# Uncomment the following line to require a user to be in the "wheel" group.
#auth           required        pam_wheel.so use_uid
auth            substack        system-auth
auth            include         postlogin
account         sufficient      pam_succeed_if.so uid = 0 use_uid quiet
account         include         system-auth
password        include         system-auth
session         include         system-auth
session         include         postlogin
session         optional        pam_xauth.so

含义

1. auth requi