Adduser devel - Nov 2005 - Bug#336843: adduser: removes user from group if /etc/group file ends with ":"

Package: adduser
Version: 3.77
Severity: normal

If a line in /etc/group ends with a colon, adduser user group removes
the last user listed in /etc/group:

$ cat /etc/group | grep ^adm
adm:x:4:Debian-console-log,mh:
$ sudo adduser --debug Debian-exim adm
Adding user Debian-exim'' to group adm''...
Done.
$ cat /etc/group | grep ^adm
adm:x:4:Debian-console-log,Debian-exim
$

Setting $verbose=2 prior to the systemcall() in the adduser code
reveals that adduser calls
/usr/bin/gpasswd -M Debian-console-log,Debian-exim adm
so it is really adduser''s fault that mh vanishes from the user list.

Greetings
Marc


-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, ''unstable''), (500,
''stable'')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.14-zgsrv
Locale: LANG=C, LC_CTYPE=de_DE (charmap=ISO-8859-1)

Versions of packages adduser depends on:
ii  debconf [debconf-2.0]         1.4.58     Debian configuration management sy
ii  passwd                        1:4.0.13-3 change and administer password and
ii  perl-base                     5.8.7-7    The Pathologically Eclectic Rubbis

adduser recommends no packages.

-- debconf information:
* adduser/homedir-permission: true

reassign #336843 perl
retitle #336843 getgrnam returns trailing ":" in user name
thanks

On Tue, Nov 01, 2005 at 05:43:40PM +0100, Marc Haber
wrote:
> If a line in /etc/group ends with a colon, adduser user group removes
> the last user listed in /etc/group:
> 
> $ cat /etc/group | grep ^adm
> adm:x:4:Debian-console-log,mh:
> $ sudo adduser --debug Debian-exim adm
> Adding user Debian-exim'' to group adm''...
> Done.
> $ cat /etc/group | grep ^adm
> adm:x:4:Debian-console-log,Debian-exim
> $
> 
> Setting $verbose=2 prior to the systemcall() in the adduser code
> reveals that adduser calls
> /usr/bin/gpasswd -M Debian-console-log,Debian-exim adm
> so it is really adduser''s fault that mh vanishes from the user
list.
Actually, it''s perl''s fault:
$ grep ''^wheel'' /etc/group
wheel:x:104:mh,scyadmin
$ perl -e ''foreach (split(/ /,
(getgrnam("wheel"))[3])) { print "$_\n"; };''
mh
scyadmin
$ grep ''^wheel'' /etc/group
wheel:x:104:mh,scyadmin:
$ perl -e ''foreach (split(/ /,
(getgrnam("wheel"))[3])) { print "$_\n"; };''
mh
scyadmin:
[12/511]mh@scyw00225:~$

Judged that ":" is the field separator in /etc/group, and that
/etc/group might change its format to include more fields, and that a
colon is not a valid character in a user name (it would wreck havoc in
/etc/passwd), I would expect that perl would consider the ":" a
delimiter here and not return it as part of the group name.

Greetings
Marc

-- 
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Marc Haber         | "I don''t trust Computers. They | Mailadresse
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Processing commands for control@bugs.debian.org:
> reassign #336843 perl
Bug#336843: adduser: removes user from group if /etc/group file ends with
":"
Bug reassigned from package `adduser'' to `perl''.
> retitle #336843 getgrnam returns trailing ":" in user name
Bug#336843: adduser: removes user from group if /etc/group file ends with
":"
Changed Bug title.
> thanks
Stopping processing here.

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