Debian Bug report logs - #145430
deluser 3.47 when multiple usernames correspond to a single uid

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

From: jon <jon@elephants.org>

To: submit@bugs.debian.org

Subject: deluser 3.47 when multiple usernames correspond to a single uid

Date: Wed, 1 May 2002 14:48:34 -0400 (EDT)

package: adduser 3.47

deluser 3.47 deletes accounts by (numerical) UID. Multiple users can
correspond to a UID, deluser provides no confirmation/sanity checks in
this case. This is entirely consistent, but it can result in
surprising results.

ie: The sash shell package can (depending on configs) create a
'sashroot' emergency maintenance account, UID=0. 
"deluser --remove-all-files sashroot"  resulted in a nasty surprise.

suggestion: 
   check for multpile users sharing the same numerical ID,
print all user names, and prompt for confirmation before proceeding.

best regards,
jon

Message #14 received at 145430-quiet@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: jon <jon@elephants.org>

Cc: 145430-quiet@bugs.debian.org, 145430-submitter@bugs.debian.org

Subject: Re: deluser 3.47 when multiple usernames correspond to a single uid

Date: Wed, 24 Mar 2004 11:37:09 +0100

tags #145430 help
thanks

On Wed, May 01, 2002 at 02:48:34PM -0400, jon wrote:
> ie: The sash shell package can (depending on configs) create a
> 'sashroot' emergency maintenance account, UID=0. 
> "deluser --remove-all-files sashroot"  resulted in a nasty surprise.

Never delete an account without checking its home directory first.

> suggestion: 
>    check for multpile users sharing the same numerical ID,
> print all user names, and prompt for confirmation before proceeding.

I don't like the idea of having deluser going interactive since it is
frequently called from scripts.

I don't see an easy fix for this problem without doing major re-work
on deluser and would like to ask for suggestions.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Karlsruhe, Germany |  lose things."    Winona Ryder | Fon: *49 721 966 32 15
Nordisch by Nature |  How to make an American Quilt | Fax: *49 721 966 31 29

Message #22 received at 145430-quiet@bugs.debian.org (full text, mbox, reply):

From: Joerg Hoh <joerg@joerghoh.de>

To: jon <jon@elephants.org>

Cc: 145430-quiet@bugs.debian.org, 145430-submitter@bugs.debian.org

Subject: Re: Bug#145430: deluser 3.47 when multiple usernames correspond to a single uid

Date: Wed, 27 Jun 2007 22:52:08 +0200

[Message part 1 (text/plain, inline)]

On Mittwoch 24 März 2004, Marc Haber wrote:

> On Wed, May 01, 2002 at 02:48:34PM -0400, jon wrote:
> > ie: The sash shell package can (depending on configs) create a
> > 'sashroot' emergency maintenance account, UID=0.
> > "deluser --remove-all-files sashroot"  resulted in a nasty surprise.

The whole unix password stuff doesn't support such a config very well. E.g the 
getpwnam* functions do return exactly none or one result when requesting the 
username for the user with uid = 0.

> I don't see an easy fix for this problem without doing major re-work
> on deluser and would like to ask for suggestions.

This is getting rather complicated because such a request is not supported by 
standard libc functions like getpw*. We had to parse /etc/passwd manually for 
such a double entry. This will result in rather unportable code which doesn't 
cope very well with NIS and LDAP.

Jörg

-- 
What did you do to the cat? It looks half-dead. -Schroedinger's wife

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Message #30 received at 145430-quiet@bugs.debian.org (full text, mbox, reply):

From: "Jon Shickel" <jon@elephants.org>

To: "Joerg Hoh" <joerg@joerghoh.de>

Cc: 145430-quiet@bugs.debian.org, 145430-submitter@bugs.debian.org

Subject: Re: Bug#145430: deluser 3.47 when multiple usernames correspond to a single uid

Date: Wed, 4 Jul 2007 13:29:04 -0400

On 6/27/07, Joerg Hoh <joerg@joerghoh.de> wrote:
> On Mittwoch 24 März 2004, Marc Haber wrote:
>
> > On Wed, May 01, 2002 at 02:48:34PM -0400, jon wrote:
> > > ie: The sash shell package can (depending on configs) create a
> > > 'sashroot' emergency maintenance account, UID=0.
> > > "deluser --remove-all-files sashroot"  resulted in a nasty surprise.
>
> The whole unix password stuff doesn't support such a config very well. E.g the
> getpwnam* functions do return exactly none or one result when requesting the
> username for the user with uid = 0.
>
> > I don't see an easy fix for this problem without doing major re-work
> > on deluser and would like to ask for suggestions.
>
> This is getting rather complicated because such a request is not supported by
> standard libc functions like getpw*. We had to parse /etc/passwd manually for
> such a double entry. This will result in rather unportable code which doesn't
> cope very well with NIS and LDAP.
> Jörg

Wow, that was a while ago! Thanks for including me.

I am of mixed mind about this. I can clearly see the utility of a
static shell account.
Yet, as you note, unix doesn't support multiple users with the same
UID gracefully
and it deleted almost all of my system before it died.

I tend to think the sash package is most to blame for introducing a second root
account. I think the sash account should probably warn users of the consequences
and to manually remove the sashroot account if they chance their
minds. This doesn't
take care of cases where one administrator creates it and another user
deletes it.

Out of curiosity, does it ever make sense to allow deluser to remove
UID = 0 account?
If it is the true root account, the system probably wouldn't be usable
would it? If it isn't
true root, well, bad things can happen. I know this goes against the
general unix theology
of letting the user do what he want, but it seems like all outcomes in
this case are bad.

Jon

Message #38 received at 145430-quiet@bugs.debian.org (full text, mbox, reply):

From: Joerg Hoh <joerg@joerghoh.de>

To: Jon Shickel <jon@elephants.org>

Cc: 145430-quiet@bugs.debian.org, 145430-submitter@bugs.debian.org

Subject: Re: Bug#145430: deluser 3.47 when multiple usernames correspond to a single uid

Date: Wed, 4 Jul 2007 19:46:41 +0200

[Message part 1 (text/plain, inline)]

Hi

On Wed, Jul 04, 2007 at 01:29:04PM -0400, Jon Shickel wrote:
> 
> Wow, that was a while ago! Thanks for including me.
>

I just try to get rid of the old cruft lying around in the bts :-)

> I am of mixed mind about this. I can clearly see the utility of a
> static shell account.
> Yet, as you note, unix doesn't support multiple users with the same
> UID gracefully
> and it deleted almost all of my system before it died.
> 
> I tend to think the sash package is most to blame for introducing a second 
> root
> account. I think the sash account should probably warn users of the 
> consequences
> and to manually remove the sashroot account if they chance their
> minds. This doesn't
> take care of cases where one administrator creates it and another user
> deletes it.

This seems to be the best solution being sash the only package I'm aware of
which introduces such a thing. 

> Out of curiosity, does it ever make sense to allow deluser to remove
> UID = 0 account?

Adding a warning shouldn't be a problem.

Jörg

-- 
What did you do to the cat? It looks half-dead. -Schroedinger's wife

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Message #46 received at 145430-close@bugs.debian.org (full text, mbox, reply):

From: Stephen Gran <sgran@debian.org>

To: 145430-close@bugs.debian.org

Subject: Bug#145430: fixed in adduser 3.106

Date: Sun, 02 Mar 2008 17:17:02 +0000

Source: adduser
Source-Version: 3.106

We believe that the bug you reported is fixed in the latest version of
adduser, which is due to be installed in the Debian FTP archive:

adduser_3.106.dsc
  to pool/main/a/adduser/adduser_3.106.dsc
adduser_3.106.tar.gz
  to pool/main/a/adduser/adduser_3.106.tar.gz
adduser_3.106_all.deb
  to pool/main/a/adduser/adduser_3.106_all.deb



A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 145430@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Stephen Gran <sgran@debian.org> (supplier of updated adduser package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@debian.org)


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Hash: SHA1

Format: 1.7
Date: Sun, 02 Mar 2008 16:57:21 +0000
Source: adduser
Binary: adduser
Architecture: source all
Version: 3.106
Distribution: unstable
Urgency: low
Maintainer: Debian Adduser Developers <adduser-devel@lists.alioth.debian.org>
Changed-By: Stephen Gran <sgran@debian.org>
Description: 
 adduser    - add and remove users and groups
Closes: 145430 435778 439212 442203 447104 447868 451321 451967 452289 452290 453419 454928 468152
Changes: 
 adduser (3.106) unstable; urgency=low
 .
   [ Joerg Hoh ]
   * adduser exits with returncode 1 if trying to add an already existing user
     as system user. Thanks to Vincent Bernat; Closes: #435778
   * deluser: warn if you want to remove the root account. Closes: #145430
   * deluser: fix backup when bzip2 is not available. Closes: #453419
   * deluser: print correct warning when you removed the last user in a group;
     thanks Marc 'Zugschlus' Haber and Peter Eisentraut
     (Closes: #454928,#451967)
 .
   [ Stephen Gran ]
   * Translation:
     be (thanks Pavel Piatruk <berserker@neolocation.com>)( closes: #447104)
     fr (thanks Nicolas François <nicolas.francois@centraliens.net>)
     (closes: #442203)
     ru (thanks Yuri Kozlov <kozlov.y@gmail.com>)(closes: #452289, #452290)
     sk (thanks Ivan Masár <helix84@centrum.sk>)(closes: #439212)
     zh_CN (thanks LI Daobing <lidaobing@gmail.com>)(closes: #447868)
   * Clarify --in-group documentation (closes: #468152)
   * deluser: Let tar gzip/bzip backups directly (closes: #451321)
   * Update Standards Version (no changes)
   * Homepage, Vcs-Svn and Vcs-Browser fields added
   * Do nothing in binary-arch
Files: 
 542e266dab99f99dea31a4ba016fd7d7 835 admin important adduser_3.106.dsc
 3329395cc47d3f5f147e87028736387b 262830 admin important adduser_3.106.tar.gz
 be4885c8629de328cc18cff8352d280e 183366 admin important adduser_3.106_all.deb

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