NAME | SYNOPSIS | DESCRIPTION | OPTIONS | MODULE TYPES PROVIDED | RETURN VALUES | FILES | SEE ALSO | AUTHORS | COLOPHON

PAM_GROUP(8)                  Linux-PAM Manual                  PAM_GROUP(8)

NAME         top

       pam_group - PAM module for group access

SYNOPSIS         top

       pam_group.so

DESCRIPTION         top

       The pam_group PAM module does not authenticate the user, but instead
       it grants group memberships (in the credential setting phase of the
       authentication module) to the user. Such memberships are based on the
       service they are applying for.

       By default rules for group memberships are taken from config file
       /etc/security/group.conf.

       This module's usefulness relies on the file-systems accessible to the
       user. The point being that once granted the membership of a group,
       the user may attempt to create a setgid binary with a restricted
       group ownership. Later, when the user is not given membership to this
       group, they can recover group membership with the precompiled binary.
       The reason that the file-systems that the user has access to are so
       significant, is the fact that when a system is mounted nosuid the
       user is unable to create or execute such a binary file. For this
       module to provide any level of security, all file-systems that the
       user has write access to should be mounted nosuid.

       The pam_group module functions in parallel with the /etc/group file.
       If the user is granted any groups based on the behavior of this
       module, they are granted in addition to those entries /etc/group (or
       equivalent).

OPTIONS         top

       This module does not recognise any options.

MODULE TYPES PROVIDED         top

       Only the auth module type is provided.

RETURN VALUES         top

       PAM_SUCCESS
           group membership was granted.

       PAM_ABORT
           Not all relevant data could be gotten.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_CRED_ERR
           Group membership was not granted.

       PAM_IGNORE
           pam_sm_authenticate was called which does nothing.

       PAM_USER_UNKNOWN
           The user is not known to the system.

FILES         top

       /etc/security/group.conf
           Default configuration file

SEE ALSO         top

       group.conf(5), pam.d(5), pam(8).

AUTHORS         top

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

COLOPHON         top

       This page is part of the linux-pam (Pluggable Authentication Modules
       for Linux) project.  Information about the project can be found at 
       ⟨http://www.linux-pam.org/⟩.  If you have a bug report for this manual
       page, see ⟨//www.linux-pam.org/⟩.  This page was obtained from the
       tarball Linux-PAM-1.3.0.tar.gz fetched from 
       ⟨http://www.linux-pam.org/library/⟩ on 2017-05-03.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

Linux-PAM Manual                 04/01/2016                     PAM_GROUP(8)

Pages that refer to this page: group.conf(5)