Panic or Segfault in Samba / Message comes for about a week several times a day

[Stefan Reppenhagen]

Betriebssystem ‪Ubuntu 16.04.6 LTS‬
Produkt Plesk Onyx
Version 17.8.11 Update #53, zuletzt aktualisiert: 21. Mai 2019 05:47:33

The Samba 'panic action' script, /usr/share/samba/panic-action, was called for PID 3090 (/usr/sbin/smbd).

This means there was a problem with the program, such as a segfault.
Below is a backtrace for this process generated with gdb, which shows the state of the program at the time the error occurred. The Samba log files may contain additional information about the problem.

If the problem persists, you are encouraged to first install the samba-dbg package, which contains the debugging symbols for the Samba binaries. Then submit the provided information as a bug report to Ubuntu by visiting this link:
https://launchpad.net/ubuntu/+source/samba/+filebug

[Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007fc1cff4a07a in __GI___waitpid (pid=3092, stat_loc=stat_loc@entry=0x7ffe31557f90, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
#0 0x00007fc1cff4a07a in __GI___waitpid (pid=3092, stat_loc=stat_loc@entry=0x7ffe31557f90, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
#1 0x00007fc1cfec2fbb in do_system (line=<optimized out>) at ../sysdeps/posix/system.c:148
#2 0x00007fc1d296e8d1 in smb_panic_s3 () from /usr/lib/x86_64-linux-gnu/samba/libsmbregistry.so.0
#3 0x00007fc1d36e1f1f in smb_panic () from /usr/lib/x86_64-linux-gnu/libsamba-util.so.0
#4 0x00007fc1d36e2136 in ?? () from /usr/lib/x86_64-linux-gnu/libsamba-util.so.0
#5 <signal handler called>
#6 0x00007fc1d32dac6f in smbXsrv_session_create () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#7 0x00007fc1d3273643 in reply_sesssetup_and_X () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#8 0x00007fc1d32afe67 in ?? () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#9 0x00007fc1d32b1bb3 in ?? () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#10 0x00007fc1d32b321c in ?? () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#11 0x00007fc1d1601917 in run_events_poll () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#12 0x00007fc1d1601b77 in ?? () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#13 0x00007fc1d024bd3d in _tevent_loop_once () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#14 0x00007fc1d024bedb in tevent_common_loop_wait () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#15 0x00007fc1d32b4578 in smbd_process () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#16 0x000055661100fe12 in ?? ()
#17 0x00007fc1d1601917 in run_events_poll () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#18 0x00007fc1d1601b77 in ?? () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#19 0x00007fc1d024bd3d in _tevent_loop_once () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#20 0x00007fc1d024bedb in tevent_common_loop_wait () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#21 0x000055661100e099 in main ()
A debugging session is active.

 Inferior 1 [process 3090] will be detached.

Quit anyway? (y or n) [answered Y; input not from terminal]

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please answer these questions:
* Is this reproducible?
* If so, what specific steps should we take to recreate this bug?

This will help us to find and resolve the problem.

[Stefan Reppenhagen (messerjack101)]

Hello. Thank you for your prompt reply.

Unfortunately, I am not a professional and manage my web server quite simply using the Plesk interface.

The error messages come for about two weeks and I have the impression they are piling up.

Also, the PID values change. First came the following message:

---

The Samba 'panic action' script, /usr/share/samba/panic-action, was called for PID 9108 (/usr/sbin/smbd).

This means there was a problem with the program, such as a segfault.
However, gdb was not found on your system, so the error could not be debugged. Please install the gdb package so that debugging information is available the next time such a problem occurs.

---

Today I have this gdb package installed and since then comes the more detailed message. 2 weeks ago I got the message the first time. Last week then again. Yesterday twice and today already 3 times.

Also temporally I can not recognize a system. Completely different days and times. After a restart of the server, I get directly a mail.

[Stefan Reppenhagen (messerjack101)]

The next error-mail has just arrived. Now he would like to have another package installed.

---

The Samba 'panic action' script, /usr/share/samba/panic-action, was called for PID 7887 (/usr/sbin/smbd).

This means there was a problem with the program, such as a segfault.
Below is a backtrace for this process generated with gdb, which shows the state of the program at the time the error occurred. The Samba log files may contain additional information about the problem.

If the problem persists, you are encouraged to first install the samba-dbg package, which contains the debugging symbols for the Samba binaries. Then submit the provided information as a bug report to Ubuntu by visiting this link:
https://launchpad.net/ubuntu/+source/samba/+filebug

[Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007fc1cff4a07a in __GI___waitpid (pid=7889, stat_loc=stat_loc@entry=0x7ffe31557f90, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
#0 0x00007fc1cff4a07a in __GI___waitpid (pid=7889, stat_loc=stat_loc@entry=0x7ffe31557f90, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:29
#1 0x00007fc1cfec2fbb in do_system (line=<optimized out>) at ../sysdeps/posix/system.c:148
#2 0x00007fc1d296e8d1 in smb_panic_s3 () from /usr/lib/x86_64-linux-gnu/samba/libsmbregistry.so.0
#3 0x00007fc1d36e1f1f in smb_panic () from /usr/lib/x86_64-linux-gnu/libsamba-util.so.0
#4 0x00007fc1d36e2136 in ?? () from /usr/lib/x86_64-linux-gnu/libsamba-util.so.0
#5 <signal handler called>
#6 0x00007fc1d32dac6f in smbXsrv_session_create () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#7 0x00007fc1d3273643 in reply_sesssetup_and_X () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#8 0x00007fc1d32afe67 in ?? () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#9 0x00007fc1d32b1bb3 in ?? () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#10 0x00007fc1d32b321c in ?? () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#11 0x00007fc1d1601917 in run_events_poll () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#12 0x00007fc1d1601b77 in ?? () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#13 0x00007fc1d024bd3d in _tevent_loop_once () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#14 0x00007fc1d024bedb in tevent_common_loop_wait () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#15 0x00007fc1d32b4578 in smbd_process () from /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0
#16 0x000055661100fe12 in ?? ()
#17 0x00007fc1d1601917 in run_events_poll () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#18 0x00007fc1d1601b77 in ?? () from /usr/lib/x86_64-linux-gnu/libsmbconf.so.0
#19 0x00007fc1d024bd3d in _tevent_loop_once () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#20 0x00007fc1d024bedb in tevent_common_loop_wait () from /usr/lib/x86_64-linux-gnu/libtevent.so.0
#21 0x000055661100e099 in main ()
A debugging session is active.

 Inferior 1 [process 7887] will be detached.

Quit anyway? (y or n) [answered Y; input not from terminal]

[Andreas Hasenack (ahasenack)]

Can you please run this command on the affected samba server? It will attach log information to this bug, and we can go from there:

sudo apport-collect -p samba 1829822

I'm not sure at the moment if it will attach crash files from /var/crash, but if it doesn't, and you find samba (smbd perhaps) crash files in that directory, please attach the latest one.

Thanks!

[Sebastien Bacher (seb128)]

Did those problems start after an update? Could you try if going back to that version fixes the problem?
https://launchpad.net/~ubuntu-security/+archive/ubuntu/ppa/+build/15679398

[Stefan Reppenhagen (messerjack101)]

Unfortunately, he does not find the apport-collect command and I can not find a crash folder in root / var.

I do not trust myself to roll back to a previous version of the samba service. I'll probably wait for the next version, which hopefully will update itself then.

[Sebastien Bacher (seb128)]

> he does not find the apport-collect command

weird, maybe you don't have apport installed? ($ sudo apt install apport)

Could you at least install the debug packages and copy the error output again next time (it should then contain more info)

Download those
$ wget https://launchpad.net/~ubuntu-security/+archive/ubuntu/ppa/+build/16754210/+files/samba-dbg_4.3.11+dfsg-0ubuntu0.16.04.20_amd64.deb
$ sudo dpkg -i samba-dbg_4.3.11+dfsg-0ubuntu0.16.04.20_amd64.deb

[Stefan Reppenhagen (messerjack101)]

All right. I have the 3 things installed and post the next bug report here.

[Stefan Reppenhagen (messerjack101)]

> weird, maybe you don't have apport installed?

I had no idea that I have Samba installed ^^

[Andreas Hasenack (ahasenack)]

This may be https://bugzilla.samba.org/show_bug.cgi?id=13315, found also in https://bugzilla.samba.org/show_bug.cgi?id=13315, but we don't even have the crash file and I can't reproduce it at the moment by just connecting using SMB1: it won't crash.