LinuxQuestions.org
LinuxAnswers - the LQ Linux tutorial section.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices

Reply
 
Search this Thread
Old 03-05-2005, 12:31 PM   #1
exodist
Senior Member
 
Registered: Aug 2003
Location: Portland, Oregon
Distribution: Gentoo
Posts: 1,372

Rep: Reputation: 46
su root authentication failure


as a user added to the wheel group in gentoo linux I try 'su root' it asks me for a password I enter the correct password (I can doa root login fine, su is only problem) it gives me the error:

su: Authentication failue
sorry


the user in question has been added to the wheel group
 
Old 03-05-2005, 12:41 PM   #2
harken
Member
 
Registered: Jan 2005
Location: Between the chair and the desk
Distribution: Debian Sarge, kernel 2.6.13
Posts: 666

Rep: Reputation: 30
I had a similar problem, the difference being that I tried to assign the /bin/su file to the group wheel after creating the group.
Check and see if /bin/su has the suid bit set.
Hope this will solve your problem.
 
Old 03-05-2005, 12:54 PM   #3
exodist
Senior Member
 
Registered: Aug 2003
Location: Portland, Oregon
Distribution: Gentoo
Posts: 1,372

Original Poster
Rep: Reputation: 46
thanx, chmod +s /bin/su fixed it.
 
Old 04-02-2005, 09:43 PM   #4
fclock
LQ Newbie
 
Registered: Apr 2005
Distribution: CentOS & DeLi Linux
Posts: 2

Rep: Reputation: 0
Apparently `su' didn't have setuid bit set.

Run as root:

chmod +s /bin/su

and su should work better.
 
Old 03-26-2009, 08:08 AM   #5
cdoebbler
LQ Newbie
 
Registered: Mar 2009
Posts: 2

Rep: Reputation: 0
Unhappy authentication failure for su

When I run su I get an error message "authentication failure". I then run
"chmod +s /bin/su" and I get an error message saying that

chmod: changing permissions of 'bin/su': Operation not permitted

Apparently su like most of my files are locked because of the system crash that I am trying to repair. Any suggestions how to unlock or find password for su?
 
Old 04-04-2009, 04:47 PM   #6
raedbenz
Member
 
Registered: Dec 2007
Posts: 93

Rep: Reputation: 15
Quote:
Originally Posted by cdoebbler View Post
When I run su I get an error message "authentication failure". I then run
"chmod +s /bin/su" and I get an error message saying that

chmod: changing permissions of 'bin/su': Operation not permitted

Apparently su like most of my files are locked because of the system crash that I am trying to repair. Any suggestions how to unlock or find password for su?
have u tried to "sudo -i" first, then enter "chmod +s /bin/su"
 
Old 08-03-2010, 09:20 PM   #7
triva911
LQ Newbie
 
Registered: Aug 2010
Posts: 1

Rep: Reputation: 0
Quote:
Originally Posted by raedbenz View Post
have u tried to "sudo -i" first, then enter "chmod +s /bin/su"
Thanks Man Very Much .... sudo -i command save my day ......thanks again...
 
Old 08-05-2011, 05:03 PM   #8
lvcosme
LQ Newbie
 
Registered: Aug 2011
Posts: 4

Rep: Reputation: Disabled
Quote:
Originally Posted by cdoebbler View Post
When I run su I get an error message "authentication failure". I then run
"chmod +s /bin/su" and I get an error message saying that

chmod: changing permissions of 'bin/su': Operation not permitted

Apparently su like most of my files are locked because of the system crash that I am trying to repair. Any suggestions how to unlock or find password for su?
I have the same problem, but then when I run sudo -i I get "sudo: must be setuid root". How can I go around it. I can't get too the root to change sudo ^^
 
Old 08-05-2011, 08:24 PM   #9
exodist
Senior Member
 
Registered: Aug 2003
Location: Portland, Oregon
Distribution: Gentoo
Posts: 1,372

Original Poster
Rep: Reputation: 46
you have to login as root and set chmod +s /bin/su and /bin/sudo
 
Old 08-06-2011, 02:31 PM   #10
lvcosme
LQ Newbie
 
Registered: Aug 2011
Posts: 4

Rep: Reputation: Disabled
Hey thanks. I wish I could log as root, but I can't. I even tried this http://www.psychocats.net/ubuntu/fixsudo but did not work. I will backup and reinstall. If I try sudo -i, then I get "sudo: must be setuid root", if I run su, then I get "su: Authentication failue". I logged in the repair mode (as root) and run chmod +s /bin/su, did not work either. Somehow I messed up sudoers/sudo badly.
 
  


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
su root: authentication failure (password correct) scs_24 Linux - Newbie 3 12-12-2009 01:07 AM
dialup authentication failure raypuddy Linux - General 8 05-22-2005 05:00 PM
I cant su anymore (authentication failure) Mr.Ampersand() Linux - Newbie 4 03-22-2005 08:29 AM
UT2004 Authentication failure darkaudti Linux - Games 9 08-31-2004 04:31 PM
authentication failure mendiratta Linux - Security 1 07-03-2004 03:20 AM


All times are GMT -5. The time now is 05:00 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