pam_tally2 does not show address of the failing user

Question

See this output below:

# pam_tally2 -u
Login           Failures Latest failure     From
root                1    04/16/14 16:44:16  10.4.1.189
greg                2    04/16/14 16:35:57  unknown

Why would there be no address 'greg' logged from? Hexdump of the /var/log/tallylog file contains verbatim 'unknown' so it suggests me that PAM did not register source.

Any idea why?

Just for any case here us my /etc/pam.d/system-auth-ac file (system-auth is a soft link to system-auth-ac):

# cat /etc/pam.d/system-auth-ac
#%PAM-1.0
# This file is auto-generated.
# User changes will be destroyed the next time authconfig is run.
auth        required      pam_tally2.so deny=3 even_deny_root unlock_time=120
auth        required      pam_env.so
auth        sufficient    pam_unix.so nullok try_first_pass
auth        requisite     pam_succeed_if.so uid >= 500 quiet
auth        required      pam_deny.so

account     required      pam_tally2.so
account     required      pam_unix.so
account     sufficient    pam_succeed_if.so uid < 500 quiet
account     required      pam_permit.so

password    requisite     pam_cracklib.so retry=3 minlen=8 ucredit=-1 dcredit=-1 ocredit=-1 lcredit=-1 reject_username
password    sufficient    pam_unix.so md5 shadow nullok try_first_pass use_authtok
password    required      pam_deny.so

session     optional      pam_keyinit.so revoke
session     required      pam_limits.so
session     [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid
session     required      pam_unix.so

Any hint would be greatly appreciated.

Ah - kernel 2.6.18-274.18.1.el5 rhel 5.7 (Tikanga)

Answer 1

Okey dokey. I see. It is not PAM configuration or anything like that. The code that uses PAM to login user is not setting PAM_RHOST.

PAM, in order to know the remote host, needs to call

pam_set_item(pamh, PAM_RHOST, remote_hostname) ;

So the problem is external.

I am leaving this question for anyone working on PAM and facing the same issue.