su command fails with permission denied

noahsatellite · 05-23-2004, 12:12 PM

When logged in as myself, if I open up a term and try to su, i enter the password for root and it gives me permission denied. The same password, though, if used to log in anew as root works. I can't pin down exactly when this happened, but i think it might have to do with dropline-installer, as that changed quite a few settings (doh) on my comp.

Thanks,
Noah

fur · 05-23-2004, 12:21 PM

In /etc/group you will need to add your user to the wheel group.

rottie · 05-23-2004, 12:23 PM

Which permition does the su command have on your system?
ls -l /bin/su
(or whatever location it's at, if it's not there you can find it with "whereis su")

It should be something like:
-rwsr-xr-x 1 root root 21112 2003-10-21 16:41 /bin/su

Maybe the "set user ID upon execution" thingie (s) is not set anymore.

rottie · 05-23-2004, 12:28 PM

Quote:

Originally posted by fur
In /etc/group you will need to add your user to the wheel group.

Hmm.. in my system I'm not in the wheel group but I can still use "su".

noahsatellite · 05-24-2004, 02:04 PM

Well, adding myself to the wheel group worked. Thanks a lot. While we're on the topic, what IS the wheel group, and why does it work for rottie?

Thanks,
Noah

rottie · 05-25-2004, 12:36 AM

Yes, I'm wondering too.. If someone could explain that would be nice..

alinas · 05-26-2004, 03:47 AM

In the 'old' BSD-flavoured Unices, the wheel group was used to control access to su.
An empty wheel group allowed all users to run su. Once a name was added, only those listed could do su.
Richard Stallman is famously against that mechanism, and GNU versions of su are not meant to use the wheel group for the purpose. Run "info su" to read the quote from Stallman. The wheel group is still used for confiuring sudo (see /etc/sudoers file).
Hope this helps...