[TUHS] rm command

Pete Wright pete at nomadlogic.org
Sat Apr 28 04:17:45 AEST 2018



On 04/27/2018 11:14, Steve Nickolas wrote:
> On Sat, 28 Apr 2018, Dave Horsfall wrote:
>
>> On Wed, 25 Apr 2018, Noel Chiappa wrote:
>>
>>> On early PDP-11 Unixes, 'rm' is an ordinary program, and 'rmdir' is 
>>> setuid-root, since it has to do special magic (writing into 
>>> directory files, etc). Given that, it made sense to have 'rm' run 
>>> with the least amount of privilege needed to do its job.
>>
>> I am constantly bemused by the number of "setuid root" commands, when 
>> a simple "setgid whatever" will achieve the same task.
>>
>> My mantra has always been: "If you think you need setuid root, then 
>> you are probably thinking wrong."
>>
>> My favourite here is the "ps" command:
>>
>>    On my FreeBSD server:
>>
>>     % ls -l /bin/ps
>>     -r-xr-xr-x  1 root  wheel  35640 Oct 15  2017 /bin/ps
>>
>>    On my crappy MacBook:
>>
>>     % ls -l /bin/ps
>>     -rwsr-xr-x  1 root  wheel  51200 Jul 15  2017 /bin/ps
>>
>> (I didn't check my Penguin box, because I don't think that I'll like 
>> what I'll see.)
>>
>> -- Dave
>>
>
> Debian 9:
>
> nicci at jesustheasus:~$ ls -l $(which ps)
> -rwxr-xr-x 1 root root 129336 Nov 22  2016 /bin/ps
>
> Debian 8 kFreeBSD:
>
> [usotsuki at licca ~]$ ls -l $(which ps)
> -rwxr-xr-x 1 root root 93088 Mar  6  2015 /bin/ps
>
interesting how the gnu userland marks ps as owner-writable, not sure it 
matters, but interesting...

-p

-- 
Pete Wright
pete at nomadlogic.org
@nomadlogicLA




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