Cannot su root!

FreeBSD 4.8

I am unable to su root from my user account. I can login as root, so I know I haven't forgotten the password, but if I log in as my other user, I cannot su root. When I do, it asks for my password, I type it, and it says "Sorry" like it would if I had typed it incorrectly.

Normally when something like this happens I'd back step through what I had recently done, but this is a new install (I'm new to FreeBSD altogether) and I've been doing things to it constantly, so I don't know of any "trigger" action that could have caused this.

Any ideas on what I did and what I can do to fix it?

I'd expect a different error, but the only thing I can think of is: are you sure your non-root user belongs to the wheel group?

Yes, the user is in the wheel group. I was able to su root before, but I can't say before what. I'm also now getting another repeating error related to `kdm`:
Cannot read from helper
Abnormal helper termination, code 1, signal 0
getty repeating too quickly on port /dev/ttyv9

I know how to stop this but I don't know if it's related. It too is a new problem after the same session where I lost the ability to su root.

Whew! What a mess. I guess that's part of the learning process.

I was able to fix the problem by "reinstalling" FreeBSD and rebuilding the user. This also fixed the other kdm error. All was good; I could su root from command line and then from within Konsole.

Then I issued chmod -R 0775 /usr b/c you can't move anything anywhere from within KDE's file manager b/c the only thing I own is my home directory.

It's my understanding that permissions and assigning groups and chmod-ing files was how you handled file access. So if I can't do that, what do I do? Or have I misunderstood permissions?

If you this occured during your installation, this is probably how you broke su. su needs to be setuid in order to work its magic (reading the password list and changing users). If you recursively applied 0775 to your /usr, you cleared these setuid and setgid bits from all the binaries in /usr/bin and /usr/local/bin.

If you wanted to do such a thing, you would have been better off using the symbolic syntax (say chmod -R g+w /usr) as this will not effect the other flags that need not be touched.

Beyond the normal rwx flags are the sticky bit (1000 or +t) and the setuid/setgid bits (4000/2000 and +s). If you are going to be playing around with the permissions of system binaries, you should really be familiar with them.

Hi mcgee,

I guess, I am facing the same as u said below and lost my access to root.
"If you this occured during your installation, this is probably how you broke su. su needs to be setuid in order to work its magic (reading the password list and changing users). If you recursively applied 0775 to your /usr, you cleared these setuid and setgid bits from all the binaries in /usr/bin and /usr/local/bin."

Can you tell me now, how can I get it back by login in to single user mode and setting all th permissions back ?

This is a very urgent issue.

Rgds,
weldonedp