Debian Bug report logs - #59433
hurd: group permission not honoured

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>

To: submit@bugs.debian.org

Subject: hurd: group permission not honoured

Date: Thu, 02 Mar 2000 17:10:25 +0100

Package: hurd
Version: N/A
Severity: normal

Hi,

As root:
# echo do not see > /tmp/secret
# chgrp marcus /tmp/secret
# chmod go-r /tmp/secret

Now /tmp/secret looks like this:
-rw------- root marcus tmp/secret

Now login as marcus, who belongs to group marcus and nothing else.
$ cat /tmp/secret
do not see

This might also be a glibc bug, I dunno.

Thanks,
Marcus

-- System Information
Debian Release: woody
Kernel Version: Linux ulysses 2.2.13 #1 Sat Nov 20 12:44:19 EST 1999 i586 unknown

Message #10 received at submit@bugs.debian.org (full text, mbox, reply):

From: tb@MIT.EDU (Thomas Bushnell, BSG)

To: Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>

Cc: 59433@bugs.debian.org, submit@bugs.debian.org

Subject: Re: Bug#59433: hurd: group permission not honoured

Date: 05 Mar 2000 15:48:55 -0500

Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de> writes:

> As root:
> # echo do not see > /tmp/secret
> # chgrp marcus /tmp/secret
> # chmod go-r /tmp/secret
> 
> Now /tmp/secret looks like this:
> -rw------- root marcus tmp/secret
> 
> Now login as marcus, who belongs to group marcus and nothing else.
> $ cat /tmp/secret
> do not see
> 
> This might also be a glibc bug, I dunno.

I suspect this is not a bug at all.

What is the gid marcus and what is the uid marcus?

The Hurd supports a feature known as "groupleaders".  If your uid=gid,
then you count as the owner for any files with that group. 

Thomas

Message #20 received at 59433@bugs.debian.org (full text, mbox, reply):

From: Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>

To: "Thomas Bushnell, BSG" <tb@MIT.EDU>

Cc: 59433@bugs.debian.org

Subject: Re: Bug#59433: hurd: group permission not honoured

Date: Sun, 5 Mar 2000 22:09:06 +0100

On Sun, Mar 05, 2000 at 03:48:55PM -0500, Thomas Bushnell, BSG wrote:
> Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de> writes:
> 
> > As root:
> > # echo do not see > /tmp/secret
> > # chgrp marcus /tmp/secret
> > # chmod go-r /tmp/secret
> > 
> > Now /tmp/secret looks like this:
> > -rw------- root marcus tmp/secret
> > 
> > Now login as marcus, who belongs to group marcus and nothing else.
> > $ cat /tmp/secret
> > do not see
> > 
> > This might also be a glibc bug, I dunno.
> 
> I suspect this is not a bug at all.
> 
> What is the gid marcus and what is the uid marcus?

gid=uid=1000
 
> The Hurd supports a feature known as "groupleaders".  If your uid=gid,
> then you count as the owner for any files with that group. 

Oh. That would explain it of course. I will close the report.
(Sounds like an entry for the FAQ).

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org Check Key server 
Marcus Brinkmann              GNU    http://www.gnu.org    for public PGP Key 
Marcus.Brinkmann@ruhr-uni-bochum.de,     marcus@gnu.org    PGP Key ID 36E7CD09
http://homepage.ruhr-uni-bochum.de/Marcus.Brinkmann/       brinkmd@debian.org

Message #25 received at 59433@bugs.debian.org (full text, mbox, reply):

From: Kalle Olavi Niemitalo <tosi@stekt.oulu.fi>

To: Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>

Cc: 59433@bugs.debian.org

Subject: Re: Bug#59433: hurd: group permission not honoured

Date: 06 Mar 2000 14:21:36 +0200

Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de> writes:

> On Sun, Mar 05, 2000 at 03:48:55PM -0500, Thomas Bushnell, BSG wrote:
> > The Hurd supports a feature known as "groupleaders".  If your uid=gid,
> > then you count as the owner for any files with that group. 
> 
> Oh. That would explain it of course. I will close the report.

Perhaps you should instead reassign it to adduser, as that should
be changed to avoid allocating the same id for a user and a group
unless explicitly requested (or perhaps if they have the same
name).

Message #30 received at 59433@bugs.debian.org (full text, mbox, reply):

From: tb@MIT.EDU (Thomas Bushnell, BSG)

To: Kalle Olavi Niemitalo <tosi@ees2.oulu.fi>

Cc: 59433@bugs.debian.org, Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>

Subject: Re: Bug#59433: hurd: group permission not honoured

Date: 06 Mar 2000 11:54:11 -0500

Kalle Olavi Niemitalo <tosi@ees2.oulu.fi> writes:

> Perhaps you should instead reassign it to adduser, as that should
> be changed to avoid allocating the same id for a user and a group
> unless explicitly requested (or perhaps if they have the same
> name).

Isn't the normal behavior of Debian adduser to give every user a group
which matches their ID?  That would be exactly in line with the
groupleaders concept; it meshes nicely.

Message #35 received at 59433-done@bugs.debian.org (full text, mbox, reply):

From: Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>

To: 59433-done@bugs.debian.org

Subject: foo

Date: Sat, 1 Apr 2000 16:23:45 +0200

done

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org Check Key server 
Marcus Brinkmann              GNU    http://www.gnu.org    for public PGP Key 
Marcus.Brinkmann@ruhr-uni-bochum.de,     marcus@gnu.org    PGP Key ID 36E7CD09
http://homepage.ruhr-uni-bochum.de/Marcus.Brinkmann/       brinkmd@debian.org

Message #40 received at 59433@bugs.debian.org (full text, mbox, reply):

From: Kalle Olavi Niemitalo <tosi@stekt.oulu.fi>

To: 59433@bugs.debian.org

Subject: Re: Bug#59433: hurd: group permission not honoured

Date: 09 Apr 2000 15:47:30 +0300

tb@MIT.EDU (Thomas Bushnell, BSG) writes:

> Isn't the normal behavior of Debian adduser to give every user a group
> which matches their ID?

That is what normally happens, but it isn't enforced in any way.
So if gid 1000 has been allocated earlier and uid 1000 has not, a
new user may get uid 1000 and gid 1001.  I fear this may
unexpectedly turn users to groupleaders in some cases.

If you agree, please reopen the bug and reassign it to adduser or
passwd.

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