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suddenly, login of certain users fails...

Posted on 1998-02-06
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Last Modified: 2013-12-15
Hi!

It happens sometimes that, all of a sudden, a user cannot log in anymore. And even root cannot change its password!! (passwd gives ok, but /etc/shadow is NOT changed).

I've RedHat 4.2 with shadow-support installed.

Any help appreciated!
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Question by:proffi
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5 Comments
 
LVL 2

Expert Comment

by:alexbik
ID: 1631342
Hi,

Can you reproduce this, or does it seem to be random?
Check your /etc/passwd. Could it be that users failing
to login have a different shell?

Does your /etc/shadow contain the same users as /etc/passwd?
Are the users in /etc/passwd and /etc/shadow in the same order?

Alex
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Author Comment

by:proffi
ID: 1631343
I found a workaround: If I move the user to a different location in /etc/shadow, it works again!! (whether to the top or to the bottom doesn't matter).

Of course I checked etc/passwd and /etc/shadow and /etc/group and they seem correct. All users have NO console access, only chrooted ftp to their home directory. I therefore checked the rights on their homes and they were ok, too...

What really struck me is, that passwd finished ok ("all authentication tokens updated successfully") whereas neither /etc/passwd nor /etc/shadow have been changed!

That happened now the second time since I installed RH4.2... OK I can live with it (as I now know how to proceed), but it's definitely not a feature, isn't it ? ;-(

proffi
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LVL 2

Expert Comment

by:alexbik
ID: 1631344
Have you tried another passwd program (or script)?

Alex
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LVL 4

Accepted Solution

by:
jlms earned 400 total points
ID: 1631345
Check the permissions and ownerships of both files (passwd and shadow),, maybe nobody can write to them, another thing to check are the permission of the program you use to manage these files (usually the passwd program), it should be suid-ed to allow  other users (different to root)  to modify the files.

  Check also the permissions of the /etc directory, it could be that there is no permission to modify the directory, meaning the contents is untouchable.
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Author Comment

by:proffi
ID: 1631346
Hi!

After upgrading to RH5 the problem disappeared. Thanks anyway!

I hope you got the points..

RU
theprofessor
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