LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Security
User Name
Password
Linux - Security This forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.

Notices

Reply
 
Search this Thread
Old 09-02-2003, 05:38 AM   #1
wxxg
LQ Newbie
 
Registered: Sep 2003
Posts: 2

Rep: Reputation: 0
Exclamation Redhat Linux login problem with non-root user


Hi there,

I have an SSH login problem with our newly installed RedHat Advanced Server 2.1 running on Dell PowerEdge 1750. I CAN SSH into it if I log in as root, however, if I try to log in as normal user, error message 'connection closed' will appear.

Anybody has encountered simliar problem? I don't think it's ssh problem, as I turn on sshd verbose level to DEBUG, sshd is not complaining anything. Instead, I believe it should have something to do with my PAM configuration, but I am new to PAM and cannot find anything wrong with those config files.

Here is my /etc/pam.d/sshd:

#%PAM-1.0
auth required /lib/security/pam_stack.so service=system-auth
auth required /lib/security/pam_nologin.so
account required /lib/security/pam_stack.so service=system-auth
password required /lib/security/pam_stack.so service=system-auth
session required /lib/security/pam_stack.so service=system-auth
session required /lib/security/pam_limits.so
session optional /lib/security/pam_console.so

And here is my /etc/pam.d/system-auth:

#%PAM-1.0
# This file is auto-generated.
# User changes will be destroyed the next time authconfig is run.
auth required /lib/security/pam_env.so
auth sufficient /lib/security/pam_unix.so likeauth nullok
auth required /lib/security/pam_deny.so

account required /lib/security/pam_unix.so

password required /lib/security/pam_cracklib.so retry=3 type=
password sufficient /lib/security/pam_unix.so nullok use_authtok md5 shadow
password required /lib/security/pam_deny.so

session required /lib/security/pam_limits.so
session required /lib/security/pam_unix.so

Besides, when I SSH in as root, I can find the following messages in sshd log, which are missing when I ssh in as normal user:

PAM establishing creds
channel 0: rfd 7 isatty
fd 7 setting O_NONBLOCK

Thanks in advance for your enlightenment.
 
Old 09-03-2003, 03:38 AM   #2
unSpawn
Moderator
 
Registered: May 2001
Posts: 26,953
Blog Entries: 54

Rep: Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733Reputation: 2733
Haven't seen that prob. Checking these items next to what you've already shown would be the first things I'd do:
- SSH related: the /etc/ssh/ssh_ and sshd_ configs for DenyUsers or DenyGroups directives,
- PAM related: /etc/security/limits.conf for "login" directives for the user: if you limit those, make sure ssh-enabled users are allowed logins+1,
- TCP Wrappers: /etc/hosts.(deny|allow) for any IP, group or user based blocks.
Less common would be specific netfilter (iptables) rules using extensions like string or UID match, or IP blocks. While you're at it also check the users' ~/.ssh dir for right sig and config as well, even tho I can't imagine the problem to be in ~/.ssh.

If you ssh in as that user, specifying "-v -v -v" on the cmdline should give you all excessive and gory details of the connection and handshake buildup. Scrubbing IP addy's and posting the details *could* help.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
permission problem - root is the only user which can login hitman_et Linux - Newbie 6 04-03-2005 10:12 AM
user login: no keyboard access (mouse OK) - no problem under root guillaume31 Mandriva 2 07-20-2004 12:24 PM
I have re-installed MK 9.2 but cannot login as user, login as root works. bobinglis Mandriva 2 02-22-2004 11:39 AM
can only login as root? user login doesnt work..? anyone? hacking_4_b33r Linux - General 1 02-05-2004 11:40 PM
Redhat Linux login problem with non-root user wxxg Linux - Software 0 09-01-2003 11:27 PM


All times are GMT -5. The time now is 06:17 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration