Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl-Sensitive Sunglasses
 
PerlMonks  

Re: setuid and setgid leaves user in 0 (wheel) group

by bingos (Vicar)
on Dec 17, 2010 at 12:21 UTC ( [id://877631]=note: print w/replies, xml ) Need Help??


in reply to setuid and setgid leaves user in 0 (wheel) group

According to perlvar for $):

The first number sets the effective gid, and the rest (if any) are passed to setgroups(). To get the effect of an empty list for setgroups(), just repeat the new effective gid

So:

$) = "$gid $gid";

The following code on my machine (NetBSD):

use strict; use warnings; use POSIX; my( $uid, $gid ) = qw/32767 32766/; setgid( $gid ); $) = "$gid $gid"; $( = $gid; die "Set group ($gid): $! +" if ( $( != $gid ) or ( $) != $gid ); setuid( $uid ); $> = $uid; $< = $uid; die "Set user ($uid): $!" if ( $< != $uid ) or ( $> != $uid ); print `id`;

Produces:

uid=32767(nobody) gid=32766(nogroup) groups=32766(nogroup)

Replies are listed 'Best First'.
Re^2: setuid and setgid leaves user in 0 (wheel) group
by petr999 (Acolyte) on Dec 17, 2010 at 13:26 UTC
    $) = "$gid $gid"
    Cool, it works, thanks!

Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: note [id://877631]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others wandering the Monastery: (4)
As of 2024-07-17 23:12 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?
    erzuuli‥ 🛈The London Perl and Raku Workshop takes place on 26th Oct 2024. If your company depends on Perl, please consider sponsoring and/or attending.