Your message dated Wed, 8 Oct 2014 15:14:26 +0200
with message-id <[email protected]>
and subject line Re: Bug#764457: perl: segfault in Dumper.so after upgrading to
5.20
has caused the Debian Bug report #764457,
regarding perl: segfault in Dumper.so after upgrading to 5.20
to be marked as done.
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--
764457: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=764457
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: perl-base
Version: 5.20.1-1
File: /usr/bin/perl
Hello there,
sorry for filing so late, I didn't get around any earlier ...
Some background:
On my testing system I have the Thruk Monitoring Webinterface installed
(1.84-6 as downloadable from http://www.thruk.org/download.html). Using
this webinterface creates a crontab entry for www-data:
$ sudo crontab -l -u www-data | grep -v -e '^#'
0 3 * * * cd /usr/share/thruk && /bin/bash -l -c '/usr/bin/nice -n 5
/usr/bin/thruk --local -a report=1 ' >/dev/null
2>/var/cache/thruk/reports/1.log
This cronjob worked without problems until I upgraded my perl
installation on Aug 26 2014, when I upgraded perl 5.18.2-7 -> 5.20.0-4.
Ever since this job segfaults reproducably.
:) root@fernst:~$ cat /var/cache/thruk/reports/1.log
Segmentation fault (core dumped)
Thanks to corekeeper (and ZFS snapshots) I have dumps available, the
oldest and the most recent of these dumps show
with then-current perl 5.20.0-4
:) root@fernst:~$ zgrep Dumper.so
/var/.zfs/snapshot/fernst_2014-09-01_00.00.01--12m/log/syslog-20140827.gz
Aug 27 03:00:02 fernst kernel: [1144099.516702] perl[24295]: segfault at 5 ip
00007f24d235ecee sp 00007fffe4e5e160 error 4 in Dumper.so[7f24d2358000+8000]
:) root@fernst:~$ ls -al
/var/.zfs/snapshot/fernst_2014-09-01_00.00.01--12m/crash/33/24295-33-33-11-1409101202-fernst--usr-bin-perl.core
-rw------- 1 www-data www-data 2551808 Aug 27 03:00
/var/.zfs/snapshot/fernst_2014-09-01_00.00.01--12m/crash/33/24295-33-33-11-1409101202-fernst--usr-bin-perl.core
:) root@fernst:~$ gdb
/usr/.zfs/snapshot/fernst_2014-09-01_00.00.01--12m/bin/perl
--core=/var/.zfs/snapshot/fernst_2014-09-01_00.00.01--12m/crash/33/24295-33-33-11-1409101202-fernst--usr-bin-perl.core
[...]
Reading symbols from
/usr/.zfs/snapshot/fernst_2014-09-01_00.00.01--12m/bin/perl...(no debugging
symbols found)...done.
[New LWP 24295]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `perl -x /usr/bin/thruk --local -a report=1'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f24d235ecee in boot_Data__Dumper () from
/usr/lib/thruk/perl5/x86_64-linux-gnu-thread-multi/auto/Data/Dumper/Dumper.so
(gdb) bt
#0 0x00007f24d235ecee in boot_Data__Dumper () from
/usr/lib/thruk/perl5/x86_64-linux-gnu-thread-multi/auto/Data/Dumper/Dumper.so
#1 0x00007f24d3698cfb in Perl_pp_entersub () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#2 0x00007f24d36915b6 in Perl_pp_nextstate () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#3 0x00007f24d361b255 in Perl_init_debugger () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#4 0x0000000001cbd140 in ?? ()
#5 0x0000000001d104c0 in ?? ()
#6 0x0000000000000000 in ?? ()
(gdb) quit
and with now-current perl 5.20.1-1
:) root@fernst:~$ grep Dumper.so /var/log/syslog-20141008
Oct 8 03:00:01 fernst kernel: [1234184.018335] perl[10098]: segfault at 5 ip
00007f8098fcacee sp 00007fff3a459460 error 4 in Dumper.so[7f8098fc4000+8000]
:) root@fernst:~$ ls -al
/var/crash/33/10098-33-33-11-1412730001-fernst--usr-bin-perl.core
-rw------- 1 www-data www-data 2580480 Oct 8 03:00
/var/crash/33/10098-33-33-11-1412730001-fernst--usr-bin-perl.core
:) root@fernst:~$ gdb /usr/bin/perl
--core=/var/crash/33/10098-33-33-11-1412730001-fernst--usr-bin-perl.core
[...]
Reading symbols from /usr/bin/perl...(no debugging symbols found)...done.
[New LWP 10098]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `perl -x /usr/bin/thruk --local -a report=1'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f8098fcacee in boot_Data__Dumper () from
/usr/lib/thruk/perl5/x86_64-linux-gnu-thread-multi/auto/Data/Dumper/Dumper.so
(gdb) bt
#0 0x00007f8098fcacee in boot_Data__Dumper () from
/usr/lib/thruk/perl5/x86_64-linux-gnu-thread-multi/auto/Data/Dumper/Dumper.so
#1 0x00007f809a3045ab in Perl_pp_entersub () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#2 0x00007f809a2fce46 in Perl_runops_standard () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#3 0x00007f809a2863e5 in Perl_call_sv () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#4 0x00007f809a288753 in Perl_call_list () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#5 0x00007f809a26c241 in ?? () from /usr/lib/x86_64-linux-gnu/libperl.so.5.20
#6 0x00007f809a27fa92 in Perl_newATTRSUB_x () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#7 0x00007f809a2b6341 in Perl_yyparse () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#8 0x00007f809a336542 in ?? () from /usr/lib/x86_64-linux-gnu/libperl.so.5.20
#9 0x00007f809a342120 in Perl_pp_require () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#10 0x00007f809a2fce46 in Perl_runops_standard () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#11 0x00007f809a2863e5 in Perl_call_sv () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#12 0x00007f809a288753 in Perl_call_list () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#13 0x00007f809a26c241 in ?? () from /usr/lib/x86_64-linux-gnu/libperl.so.5.20
#14 0x00007f809a27fa92 in Perl_newATTRSUB_x () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#15 0x00007f809a282b30 in Perl_utilize () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#16 0x00007f809a2b5c79 in Perl_yyparse () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#17 0x00007f809a336542 in ?? () from /usr/lib/x86_64-linux-gnu/libperl.so.5.20
#18 0x00007f809a342120 in Perl_pp_require () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#19 0x00007f809a2fce46 in Perl_runops_standard () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#20 0x00007f809a28de0e in perl_run () from
/usr/lib/x86_64-linux-gnu/libperl.so.5.20
#21 0x0000000000400e19 in main ()
(gdb) quit
At a first glance I suspected this to be somehow linked to #762256
(CVE-2014-4330: stack exhaustion bug in Data::Dumper), but the
segfaulting predates that update and definitely started with the upgrade
to perl 5.20.
I was tempted to file this bug at severity "important" as it shouldn't
segfault no matter wich script (included in Debian or not) is executed.
But I see other segfaults are kept at "normal", so I simply follow suit.
Please adjust as you see fit, and please advise on how to best further
debug this.
Cheers,
Flo
-- System Information:
Debian Release: jessie/sid
APT prefers testing
APT policy: (990, 'testing'), (50, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.16-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages perl-base depends on:
ii dpkg 1.17.13
ii libc6 2.19-11
perl-base recommends no packages.
Versions of packages perl-base suggests:
ii perl 5.20.1-1
-- no debconf information
--- End Message ---
--- Begin Message ---
Hello there,
thanks for the swift reply.
On Wed, Oct 08, 2014 at 03:43:44PM +0300, Damyan Ivanov wrote:
> [...]
> What could help is installing the 'perl-debug' package which should
> give a more verbose backtrace.
>
> Another thing would be trying to distill a small reproducible
> testcase, but that may be not so easy.
Heh, change of plans. Following the hint about perl-debug I dove into
the thruk script. What I found was that thruk ships its own perl 5.18
below /usr/lib/thruk/perl5 (for whatever reason), and mixing this perl
with Debian's perl is obviously not a good idea.
Sorry for the noise, I don't think there is anything buggy in Debian's
perl, but rather thruk seems not to have been updated / adjusted for
Debian's perl migration. But this doesn't affect Debian, so closing the
bug.
Cheers,
Flo
--- End Message ---
