su

[dieter flunkert]

Hey all,
I have a question concerning su. If I use su which is on my harddisk it works fine.
But if I use the copy I have on /tmp on the ram disk, it doesn't work. It askes
for the password, but after typing in the right one, I'm still not root.
Any ideas?

Dieter

Dieter Flunkert d_flu...@cen.jrc.it

[Adrie Koolen]

In article <50...@nigel.ee.udel.edu> d_flu...@cen.jrc.it (dieter flunkert) writes:
>Hey all,
>I have a question concerning su. If I use su which is on my harddisk it works fine.
>But if I use the copy I have on /tmp on the ram disk, it doesn't work. It askes
>for the password, but after typing in the right one, I'm still not root.
>Any ideas?

su should be owned by root and should be setuid. Only a root process can
change its user ID. So you should login as root, then copy su and set the
setuid bit:

# cp /usr/bin/su /tmp
# chmod u+s /tmp/su

Then it should work.

Adrie Koolen (ad...@ica.philips.nl)
Philips Innovation Centre Aachen

[Christian Lampl]

dieter flunkert <d_flu...@cen.jrc.it> writes:

>Dieter

>Dieter Flunkert d_flu...@cen.jrc.it

Try :
$ cd /tmp
$ chmod 4755 su

That must be all !!!

--
c...@dobag.in-berlin.de |-An optimist believes we live in the best world |
Christian Lampl | possible; a pessimist fears this is true !! |
Berlin, Germany |-There are no bugs, only unrecognized features !! |

[Joerg Conradt]

c...@dobag.in-berlin.de (Christian Lampl) writes:

>dieter flunkert <d_flu...@cen.jrc.it> writes:

>>Hey all,
>>I have a question concerning su. If I use su which is on my harddisk it works fine.
>>But if I use the copy I have on /tmp on the ram disk, it doesn't work. It askes
>>for the password, but after typing in the right one, I'm still not root.
>>Any ideas?

>>Dieter

>>Dieter Flunkert d_flu...@cen.jrc.it

>Try :
>$ cd /tmp
>$ chmod 4755 su

>That must be all !!!

>Christian Lampl UUCP: c...@dobag.in-berlin.de

Oh no, Christian!!!!!!

Of course you first have to change dir. to /tmp and then exec the chmod
command! Though a correct way to make it work would be:

<Log in as root>
cd /tmp
chmod 4755 su
exit

After this it will work. The chmod command sets the s-bit, which makes the
user running the su-command root, and you have to be root if you want to
change your userid or groupid! Otherwise every user could do so and there
is no bit of system-security!!!
Cheers Joerg

--
UUCP: j...@dobag.in-berlin.de | - The number of viewers watching you is
Alias Joerg Conradt | proportional to the stupidity of your
1000 Berlin 41 Germany | action.
++ 0307958397 | - "Murphy was an optimist"

[Christian Lampl]

j...@dobag.in-berlin.de (Joerg Conradt) writes:

>c...@dobag.in-berlin.de (Christian Lampl) writes:

>>dieter flunkert <d_flu...@cen.jrc.it> writes:

>>>Hey all,
>>>I have a question concerning su. If I use su which is on my harddisk it works fine.
>>>But if I use the copy I have on /tmp on the ram disk, it doesn't work. It askes
>>>for the password, but after typing in the right one, I'm still not root.
>>>Any ideas?

>>>Dieter

>>>Dieter Flunkert d_flu...@cen.jrc.it

>>Try :
>>$ cd /tmp
>>$ chmod 4755 su

>>That must be all !!!

>>Christian Lampl UUCP: c...@dobag.in-berlin.de

>Oh no, Christian!!!!!!

>Of course you first have to change dir. to /tmp and then exec the chmod
>command! Though a correct way to make it work would be:

I did it !!!

><Log in as root>
>cd /tmp
>chmod 4755 su
>exit

>After this it will work. The chmod command sets the s-bit, which makes the
>user running the su-command root, and you have to be root if you want to
>change your userid or groupid! Otherwise every user could do so and there
>is no bit of system-security!!!
>Cheers Joerg

That's true !! I forgot to write it down !! Sorry !!
Bye
Christian !!!