Bug#628042: perl: file creation in suid Perl script no longer works

[Vincent Lefevre]

Package: perl
Version: 5.12.3-6
Severity: important

After the upgrade to perl 5.12, a file creation in a suid Perl script
no longer works. AFAIK the perl upgrade isn't supposed to introduce
backward incompatible changes (at least nothing was announced).

My script is the following:

-rwsr-sr-x 1 news news 5535 2006-03-10 13:25:34 /usr/local/bin/rpnews

It contains:

#!/usr/bin/perl -T

[...]

$< = $>;  # set real to effective uid

$ENV{'PATH'} = '/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin';

my $news = '/var/spool/news';
my $lock = "$news/rpnews.lock";

open LOCK, ">$lock" or die "$proc: can't create lock file\n$!\n";

and when running it as a normal user, I get the error:

rpnews: can't create lock file
Permission denied
zsh: exit 13    rpnews

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (900, 'testing'), (900, 'stable'), (500, 'oldstable'), (200, 'unstable')
Architecture: powerpc (ppc)

Kernel: Linux 2.6.26-1-powerpc
Locale: LANG=POSIX, LC_CTYPE=en_US.ISO8859-1 (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/bash

Versions of packages perl depends on:
ii  libbz2-1.0              1.0.5-6          high-quality block-sorting file co
ii  libc6                   2.11.2-7         Embedded GNU C Library: Shared lib
ii  libdb5.1                5.1.25-1         Berkeley v5.1 Database Libraries [
ii  libgdbm3                1.8.3-9          GNU dbm database routines (runtime
ii  perl-base               5.12.3-6         minimal Perl system
ii  perl-modules            5.12.3-6         Core Perl modules
ii  zlib1g                  1:1.2.3.4.dfsg-3 compression library - runtime

Versions of packages perl recommends:
ii  netbase                       4.44       Basic TCP/IP networking system

Versions of packages perl suggests:
ii  libterm-readline-gnu-perl     1.20-1+b2  Perl extension for the GNU ReadLin
ii  libterm-readline-perl-perl    1.0303-1   Perl implementation of Readline li
ii  make                          3.81-8.1   An utility for Directing compilati
ii  perl-doc                      5.12.3-6   Perl documentation

-- no debconf information