pam_limits - PAM module to limit resources

       pam_limits was initially written by Cristian Gafton <gafton@redhat.com>

Linux-PAM                                          07/03/2025                                      PAM_LIMITS(8)

       The pam_limits PAM module sets limits on the system resources that can be obtained in a user-session.
       Users of uid=0 are affected by this limits, too.

       By default limits are taken from the /etc/security/limits.conf config file. Then individual *.conf files
       from the /etc/security/limits.d/ directory are read. The files are parsed one after another in the order
       of "C" locale. The effect of the individual files is the same as if all the files were concatenated
       together in the order of parsing. If a config file is explicitly specified with a module option then the
       files in the above directory are not parsed.

       The module must not be called by a multithreaded application.

       If Linux PAM is compiled with audit support the module will report when it denies access based on limit
       of maximum number of concurrent login sessions.

       For the services you need resources limits (login for example) put a the following line in
       /etc/pam.d/login as the last line for that service (usually after the pam_unix session line):

           #%PAM-1.0
           #
           # Resource limits imposed on login sessions via pam_limits
           #
           session  required  pam_limits.so

       Replace "login" for each service you are using this module.

/etc/security/limits.conf
           Default configuration file

       Only the session module type is provided.

       pam_limits - PAM module to limit resources

       conf=/path/to/limits.conf
           Indicate an alternative limits.conf style configuration file to override the default.

       debug
           Print debug information.

       set_all
           Set the limits for which no value is specified in the configuration file to the one from the process
           with the PID 1. Please note that if the init process is systemd these limits will not be the kernel
           default limits and this option should not be used.

       utmp_early
           Some broken applications actually allocate a utmp entry for the user before the user is admitted to
           the system. If some of the services you are configuring PAM for do this, you can selectively use this
           module argument to compensate for this behavior and at the same time maintain system-wide consistency
           with a single limits.conf file.

       noaudit
           Do not report exceeded maximum logins count to the audit subsystem.

       PAM_ABORT
           Cannot get current limits.

       PAM_IGNORE
           No limits found for this user.

       PAM_PERM_DENIED
           New limits could not be set.

       PAM_SERVICE_ERR
           Cannot read config file.

       PAM_SESSION_ERR
           Error recovering account name.

       PAM_SUCCESS
           Limits were changed.

       PAM_USER_UNKNOWN
           The user is not known to the system.

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

pam_limits.so [conf=/path/to/limits.conf] [debug] [set_all] [utmp_early] [noaudit]