FAILLOG(8) System Manager's Manual FAILLOG(8)NAME
faillog - examine faillog and set login failure limits
SYNOPSIS
faillog [-u login-name] [-a] [-t days]
[-m max] [-pr]
DESCRIPTION
faillog formats the contents of the failure log, /var/log/faillog, and maintains failure counts and limits. The order of the arguments to
faillog is significant. Each argument is processed immediately in the order given.
The -p flag causes failure entries to be printed in UID order. Entering -u login-name flag will cause the failure record for login-name
only to be printed. Entering -t days will cause only the failures more recent than days to be printed. The -t flag overrides the use of
-u. The -a flag causes all users to be selected. When used with the -p flag, this option selects all users who have ever had a login
failure. It is meaningless with the -r flag.
The -r flag is used to reset the count of login failures. Write access to /var/log/faillog is required for this option. Entering -u
login-name will cause only the failure count for login-name to be reset.
The -m flag is used to set the maximum number of login failures before the account is disabled. Write access to /var/log/faillog is
required for this option. Entering -m max will cause all accounts to be disabled after max failed logins occur. This may be modified with
-u login-name to limit this function to login-name only. Selecting a max value of 0 has the effect of not placing a limit on the number of
failed logins. The maximum failure count should always be 0 for root to prevent a denial of services attack against the system.
Options may be combined in virtually any fashion. Each -p, -r, and -m option will cause immediate execution using any -u or -t modifier.
CAVEATS
faillog only prints out users with no successful login since the last failure. To print out a user who has had a successful login since
their last failure, you must explicitly request the user with the -u flag, or print out all users with the -a flag.
Some systems may replace /var/log with /var/adm or /usr/adm.
FILES
/var/log/faillog - failure logging file
SEE ALSO login(1), faillog(5)AUTHOR
Julianne Frances Haugh (jockgrrl@ix.netcom.com)
FAILLOG(8)
Check Out this Related Man Page
PAM_TALLY(8) Linux-PAM Manual PAM_TALLY(8)NAME
pam_tally - The login counter (tallying) module
SYNOPSIS
pam_tally.so [file=/path/to/counter] [onerr=[fail|succeed]] [magic_root] [even_deny_root_account] [deny=n] [lock_time=n] [unlock_time=n]
[per_user] [no_lock_time] [no_reset] [audit] [silent] [no_log_info]
pam_tally [--file /path/to/counter] [--user username] [--reset[=n]] [--quiet]
DESCRIPTION
This module maintains a count of attempted accesses, can reset count on success, can deny access if too many attempts fail.
pam_tally comes in two parts: pam_tally.so and pam_tally. The former is the PAM module and the latter, a stand-alone program. pam_tally is
an (optional) application which can be used to interrogate and manipulate the counter file. It can display users' counts, set individual
counts, or clear all counts. Setting artificially high counts may be useful for blocking users without changing their passwords. For
example, one might find it useful to clear all counts every midnight from a cron job. The faillog(8) command can be used instead of
pam_tally to to maintain the counter file.
Normally, failed attempts to access root will not cause the root account to become blocked, to prevent denial-of-service: if your users
aren't given shell accounts and root may only login via su or at the machine console (not telnet/rsh, etc), this is safe.
OPTIONS
GLOBAL OPTIONS
This can be used for auth and account module types.
onerr=[fail|succeed]
If something weird happens (like unable to open the file), return with PAM_SUCCESS if onerr=succeed is given, else with the
corresponding PAM error code.
file=/path/to/counter
File where to keep counts. Default is /var/log/faillog.
audit
Will log the user name into the system log if the user is not found.
silent
Don't print informative messages.
no_log_info
Don't log informative messages via syslog(3).
AUTH OPTIONS
Authentication phase first checks if user should be denied access and if not it increments attempted login counter. Then on call to
pam_setcred(3) it resets the attempts counter.
deny=n
Deny access if tally for this user exceeds n.
lock_time=n
Always deny for n seconds after failed attempt.
unlock_time=n
Allow access after n seconds after failed attempt. If this option is used the user will be locked out for the specified amount of
time after he exceeded his maximum allowed attempts. Otherwise the account is locked until the lock is removed by a manual
intervention of the system administrator.
magic_root
If the module is invoked by a user with uid=0 the counter is not incremented. The sysadmin should use this for user launched
services, like su, otherwise this argument should be omitted.
no_lock_time
Do not use the .fail_locktime field in /var/log/faillog for this user.
no_reset
Don't reset count on successful entry, only decrement.
even_deny_root_account
Root account can become unavailable.
per_user
If /var/log/faillog contains a non-zero .fail_max/.fail_locktime field for this user then use it instead of deny=n/ lock_time=n
parameter.
no_lock_time
Don't use .fail_locktime filed in /var/log/faillog for this user.
ACCOUNT OPTIONS
Account phase resets attempts counter if the user is not magic root. This phase can be used optionally for services which don't call
pam_setcred(3) correctly or if the reset should be done regardless of the failure of the account phase of other modules.
magic_root
If the module is invoked by a user with uid=0 the counter is not incremented. The sysadmin should use this for user launched
services, like su, otherwise this argument should be omitted.
no_reset
Don't reset count on successful entry, only decrement.
MODULE TYPES PROVIDED
The auth and account module types are provided.
RETURN VALUES
PAM_AUTH_ERR
A invalid option was given, the module was not able to retrieve the user name, no valid counter file was found, or too many failed
logins.
PAM_SUCCESS
Everything was successful.
PAM_USER_UNKNOWN
User not known.
EXAMPLES
Add the following line to /etc/pam.d/login to lock the account after too many failed logins. The number of allowed fails is specified by
/var/log/faillog and needs to be set with pam_tally or faillog(8) before.
auth required pam_securetty.so
auth required pam_tally.so per_user
auth required pam_env.so
auth required pam_unix.so
auth required pam_nologin.so
account required pam_unix.so
password required pam_unix.so
session required pam_limits.so
session required pam_unix.so
session required pam_lastlog.so nowtmp
session optional pam_mail.so standard
FILES
/var/log/faillog
failure logging file
SEE ALSO faillog(8), pam.conf(5), pam.d(5), pam(8)AUTHOR
pam_tally was written by Tim Baverstock and Tomas Mraz.
Linux-PAM Manual 04/01/2010 PAM_TALLY(8)