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When I press [Ctrl+Alt+F<1-6>] it takes me to tty1 through tty6 respectively, no problem. But at the login prompt, if I try to login with my username and password, it just immediately takes me back to the same login prompt. The only way I can actually log in to the console is as root.

Here're the relevant lines from my /var/log/auth.log

Nov 2 21:03:04 bhh1988-H67MA-USB3-B3 login[3116]: pam_unix(login:session): session opened for user bhh1988 by LOGIN(uid=0)
Nov 2 21:03:04 bhh1988-H67MA-USB3-B3 login[3116]: pam_unix(login:session): session closed for user bhh1988
Nov 2 21:03:53 bhh1988-H67MA-USB3-B3 login[5546]: pam_unix(login:session): session opened for user root by bhh1988(uid=0)
Nov 2 21:03:53 bhh1988-H67MA-USB3-B3 login[8258]: ROOT LOGIN on '/dev/tty1'

You see that at 21:03:04 I try to login as bhh1988, but the session just opens and immediately closes. About 50 seconds later I tried logging in as root, which is successful. Interestingly it says that the session was opened by bhh1988 (my username) though.

I also checked out /var/log/syslog and /var/log/kern.log. At the time of the login failure, I see the line:

Nov 2 21:03:04 bhh1988-H67MA-USB3-B3 kernel: [ 1430.218803] init: tty1 main process ended, respawning

Any idea what's going on, or what else I can look at for more clues?

I am on Ubuntu 12.04

EDIT:

Here is my /etc/pam.d/login file:

#
# The PAM configuration file for the Shadow `login' service
#

# Enforce a minimal delay in case of failure (in microseconds).
# (Replaces the `FAIL_DELAY' setting from login.defs)
# Note that other modules may require another minimal delay. (for example,
# to disable any delay, you should add the nodelay option to pam_unix)
auth       optional   pam_faildelay.so  delay=3000000

# Outputs an issue file prior to each login prompt (Replaces the
# ISSUE_FILE option from login.defs). Uncomment for use
# auth       required   pam_issue.so issue=/etc/issue

# Disallows root logins except on tty's listed in /etc/securetty
# (Replaces the `CONSOLE' setting from login.defs)
#
# With the default control of this module:
#   [success=ok new_authtok_reqd=ok ignore=ignore user_unknown=bad default=die]
# root will not be prompted for a password on insecure lines.
# if an invalid username is entered, a password is prompted (but login
# will eventually be rejected)
#
# You can change it to a "requisite" module if you think root may mis-type
# her login and should not be prompted for a password in that case. But
# this will leave the system as vulnerable to user enumeration attacks.
#
# You can change it to a "required" module if you think it permits to
# guess valid user names of your system (invalid user names are considered
# as possibly being root on insecure lines), but root passwords may be
# communicated over insecure lines.
auth [success=ok new_authtok_reqd=ok ignore=ignore user_unknown=bad default=die] pam_securetty.so

# Disallows other than root logins when /etc/nologin exists
# (Replaces the `NOLOGINS_FILE' option from login.defs)
auth       requisite  pam_nologin.so

# SELinux needs to be the first session rule. This ensures that any 
# lingering context has been cleared. Without out this it is possible 
# that a module could execute code in the wrong domain.
# When the module is present, "required" would be sufficient (When SELinux
# is disabled, this returns success.)
session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so close

# This module parses environment configuration file(s)
# and also allows you to use an extended config
# file /etc/security/pam_env.conf.
# 
# parsing /etc/environment needs "readenv=1"
session       required   pam_env.so readenv=1
# locale variables are also kept into /etc/default/locale in etch
# reading this file *in addition to /etc/environment* does not hurt
session       required   pam_env.so readenv=1 envfile=/etc/default/locale

# Standard Un*x authentication.
@include common-auth

# This allows certain extra groups to be granted to a user
# based on things like time of day, tty, service, and user.
# Please edit /etc/security/group.conf to fit your needs
# (Replaces the `CONSOLE_GROUPS' option in login.defs)
auth       optional   pam_group.so

# Uncomment and edit /etc/security/time.conf if you need to set
# time restrainst on logins.
# (Replaces the `PORTTIME_CHECKS_ENAB' option from login.defs
# as well as /etc/porttime)
# account    requisite  pam_time.so

# Uncomment and edit /etc/security/access.conf if you need to
# set access limits.
# (Replaces /etc/login.access file)
# account  required       pam_access.so

# Sets up user limits according to /etc/security/limits.conf
# (Replaces the use of /etc/limits in old login)
session    required   pam_limits.so

# Prints the last login info upon succesful login
# (Replaces the `LASTLOG_ENAB' option from login.defs)
session    optional   pam_lastlog.so

# Prints the motd upon succesful login
# (Replaces the `MOTD_FILE' option in login.defs)
session    optional   pam_motd.so

# Prints the status of the user's mailbox upon succesful login
# (Replaces the `MAIL_CHECK_ENAB' option from login.defs). 
#
# This also defines the MAIL environment variable
# However, userdel also needs MAIL_DIR and MAIL_FILE variables
# in /etc/login.defs to make sure that removing a user 
# also removes the user's mail spool file.
# See comments in /etc/login.defs
session    optional   pam_mail.so standard

# Standard Un*x account and session
@include common-account
@include common-session
@include common-password

# SELinux needs to intervene at login time to ensure that the process
# starts in the proper default security context. Only sessions which are
# intended to run in the user's context should be run after this.
session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so open
# When the module is present, "required" would be sufficient (When SELinux
# is disabled, this returns success.)

The only obvious thing to look for to me from this login file is the part that says:

# Disallows other than root logins when /etc/nologin exists
# (Replaces the `NOLOGINS_FILE' option from login.defs)
auth       requisite  pam_nologin.so

But I don't have an /etc/nologin so that doesn't appear to me the culprit.

share|improve this question
    
Can you provide the /etc/password line for bhh1988 (it doesnt actually contain the password - thats in /etc/shadow, but it shows the login shell. I'm wondering what the shell is set to. ALso, can you provide the output of /etc/pam,d/login - as this may be set (somehow) to only allow root logins. Also see stackoverflow.com/questions/12550779/… if you have been playing with vm.mmap_min_addr. –  davidgo Nov 3 '13 at 8:16
    
Thanks for helping. My shell in /etc/passwd is just /bin/bash –  bhh1988 Nov 3 '13 at 23:32
    
Sorry, I'm stumped !!! –  davidgo Nov 4 '13 at 8:04

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