topic Re: chown question in Operating System - Linux

chown question

Pattabhi — Wed, 03 Oct 2007 02:41:10 GMT

Gurus,

I am not able to change the ownership of a file that is owned by me to a different id. I go to /tmp create a file and then try to change the ownership by "chown" command and it says operation not permitted/not owner.

I see thi speculiar behavious only on Linux and Solaris but not on HPUX. ould nay one have an idea what is happening here?

Below exampe might give you a good idea

[ssriniva@marple ~]$ pwd
/home/ssriniva
[ssriniva@marple ~]$ id
uid=1807(ssriniva) gid=500(support) groups=500(support)
[ssriniva@marple ~]$ touch aaa
[ssriniva@marple ~]$ ls -ld aaa
-rw-r--r-- 1 ssriniva support 0 Oct 3 2007 aaa
[ssriniva@marple ~]$ chown praman1 aaa
chown: changing ownership of `aaa': Operation not permitted
[ssriniva@marple ~]$

Re: chown question

TY 007 — Wed, 03 Oct 2007 03:34:51 GMT

Hello Pattabhi,

>> behavious only on Linux
>> but not on HPUX
>> have an idea what is happening here

>> [ssriniva@marple ~]$ chown praman1 aaa
>> chown: changing ownership of `aaa': Operation not permitted

Try: [ssriniva@marple ~]$ chown ssriniva aaa
--> No Error

For Linux, may require root to change file owner to other owner.

You can try to install GNU core utilities in HP-UX OS & compare:
http://hpux.cs.utah.edu/hppd/hpux/Gnu/coreutils-6.9/

[HP-UX] $ /usr/local/coreutils/bin/chown praman1 aaa

Thanks

Re: chown question

Pattabhi — Wed, 03 Oct 2007 04:13:37 GMT

It works with core utils

[56] % cd /tmp
[57] % ls -ld a
-rw-r----- 1 praman1 support 0 Oct 3 13:01 a
[58] % id
uid=1500(praman1) gid=500(support)
[59] % /usr/local/coreutils/bin/chown reproadm a
[60] % ls -ld a
-rw-r----- 1 reproadm support 0 Oct 3 13:01 a
[61] %

and even chown ssriniva aaa also works

Re: chown question

Pattabhi — Wed, 03 Oct 2007 04:29:00 GMT

I have seen this behaviour on Linux,Solaris and AIX but on HPUX it works fine..

Re: chown question

TY 007 — Wed, 03 Oct 2007 04:38:40 GMT

Hello,

[root@marple ~]# chmod 4755 /bin/chown

[sriniva@marple ~]$ chown praman1 aaa

Possible the earlier result is expected as per design?

Thanks

Re: chown question

Pattabhi — Wed, 03 Oct 2007 05:05:55 GMT

Thanks Mate... So i can infer that it is as per design in Linux,Solaris and AIX and if you have to make it work u need to set the "set-uid" option.

REgards,
Pattabhi Raman

Re: chown question

Philip Gunter — Wed, 03 Oct 2007 22:55:34 GMT

I'd be very careful with that last suggestion. That will allow anyone on the system to chown any file.

The behaviour that you're seeing is by design on Linux/Solaris/AIX - allowing file giveaways is a bad thing.

On HP-UX it is enabled by default. Have a look at getprivgrp/setprivgrp

Cheers,
Philip.

Re: chown question

Pattabhi — Thu, 04 Oct 2007 00:46:27 GMT

Thanks for the pointers mate.

Regards,
Pattabhi RAman