On Friday 21 February 2003 7:33 am, Rob Weir wrote: > On Tue, Feb 18, 2003 at 08:59:55AM +0000, Dave Selby wrote: > > I have a query about chmod. pon is turned on by root, I want it to be > > turned off by any user. I have looked at several options, sudo, > > downgrading permissions for kill, gulp, etc etc but decided that for my > > setup using chmod and setting the user ID for poff would be the best. > > > > [EMAIL PROTECTED]:~$ su > > Password: > > debian:/home/test# chmod 4755 /usr/bin/poff > > debian:/home/test# ls -al /usr/bin/poff > > -rwsr-xr-x 1 root root 2772 Dec 10 2001 /usr/bin/poff > > debian:/home/test# > > debian:/home/test# pon > > debian:/home/test# > > debian:/home/test# exit > > exit > > [EMAIL PROTECTED]:~$ > > [EMAIL PROTECTED]:~$ poff > > /usr/bin/poff: /bin/kill failed. None stopped. > > [EMAIL PROTECTED]:~$ > > [EMAIL PROTECTED]:~$ which poff > > /usr/bin/poff > > [EMAIL PROTECTED]:~$ > > > > mmm, my ls-al seems to tell me suid has been set, as I understand it the > > process generated by calling poff from user test should now be run as > > root. As root it should kill the link started by pon. > > > > It fails when poff executes /bin/kill. Any idea why ? > > poff is a shell script. setuid scripts are massive security holes, so > the kernel refuses to honour the set{g,u}id bit on them. > > > Does SUID only apply to the called process and not any secondary > > processes ? > > The elevated permissions would be passed along, except that, as I said > above, the kernel isn't letting the script even start with setuid. My > suggestion would be to use sudo for this, since it lets you have very > tightly controlled permissions.
Ah ha that makes sense. I guess a bit of information is a dangerous thing ... seemed simple ! Many thanks for the info, I realy appreciate it dave -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]