Expiring Today—Celebrate National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

RHEL 5 : Can only log in as root

Posted on 2016-09-14
6
Medium Priority
?
52 Views
Last Modified: 2016-09-21
I rebooted my RHEL5 server today.  After discovering I couldn't remote in using ssh, I checked the console and it appeared the system was in runlevel 1 for some reason.  I rebooted again, watched the boot process and couldn't see anything significant.  I checked the runlevel, set the default runlevel to 3 and rebooted again with no effect.  I can log in to the console as root.  But, I cannot log in as any other existing user.  The login fails with no feedback.  If I try to "su - " to the user, I get a "permission" denied to the user's home directory and a "permission denied" to "/bin/bash".  I have tried to troubleshoot by adding a new user and logging in.  Same effect.

The "runlevel" command yields "N 3" which I am pretty sure means it thinks it is running in level 3 now.

All mounts seem to be OK.  I have rebooted with "-F" to force fsck, no problems.  I can navigate to all mounted volumes and access files on all of them.

I'm stumped.  The system was running and accessible when I rebooted earlier.  It is possible I mucked something up earlier when I was working on something else.  But, I am not sure what that might be.

I have crept around the web and there is rarely any mention of this problem.  When I find something, the suggestion of using "strace" is prevalent (did it, didn't reveal any permission issues that I can tell)  or some version of reinstall OS is deployed.

Anybody have any suggestions?
0
Comment
Question by:ecsginc
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 11

Expert Comment

by:loftyworm
ID: 41798694
I am no *nix guru, but I got strong suspicions that you have rooted :(

Maybe check your root boot files and see if anything is amiss

My 2 cents
0
 
LVL 11

Expert Comment

by:Scott Silva
ID: 41798894
Is there any message about damaged initrd or anything? If you have damaged boot files a system will usually drop to a minimal root session if it can get that far...
0
 

Author Comment

by:ecsginc
ID: 41801768
All boot of the errors are permissions issues similar to the su errors.  I am now thinking that somehow some uid, gid or permission got inadvertently change.  At this point I am now keying in on the sticky bit.  Does anyone have a list of standard system directories and or files where the sticky bit needs to be set?
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Accepted Solution

by:
ecsginc earned 0 total points
ID: 41802028
FYI - I solved my problem.  After scouring permissions and ownership until my eyes bled (all errors in /var/logs/dmesg and /ver/log/messages aligned with permissions issues) I threw a Hail Mary and executed "chmod 755 /".  prior to this it was more of 744.  That did the trick.

I am not sure why or how the permissions got changed (I am suspecting and errant scripting inadvertently executed as su/root with empty environment variables yielding "/" on a chmod operation).

Regardless, if anyone should end up on this thread with their own issues, changing the permissions on the root directory ("/") did the trick for me.
0
 

Author Closing Comment

by:ecsginc
ID: 41808401
I discovered the apparent cause of my original issue.
0
 
LVL 40

Expert Comment

by:omarfarid
ID: 41808426
If you have a backup for system taken before issue, then you can restore and you will get the old perms
0

Featured Post

RHCE - Red Hat OpenStack Prep Course

This course will provide in-depth training so that students who currently hold the EX200 & EX210 certifications can sit for the EX310 exam. Students will learn how to deploy & manage a full Red Hat environment with Ceph block storage, & integrate Ceph into other OpenStack service

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I. Introduction There's an interesting discussion going on now in an Experts Exchange Group — Attachments with no extension (http://www.experts-exchange.com/discussions/210281/Attachments-with-no-extension.html). This reminded me of questions tha…
Join Greg Farro and Ethan Banks from Packet Pushers (http://packetpushers.net/podcast/podcasts/pq-show-93-smart-network-monitoring-paessler-sponsored/) and Greg Ross from Paessler (https://www.paessler.com/prtg) for a discussion about smart network …
Learn how to find files with the shell using the find and locate commands. Use locate to find a needle in a haystack.: With locate, check if the file still exists.: Use find to get the actual location of the file.:
Learn how to navigate the file tree with the shell. Use pwd to print the current working directory: Use ls to list a directory's contents: Use cd to change to a new directory: Use wildcards instead of typing out long directory names: Use ../ to move…
Suggested Courses

719 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question