syslog-ng crashes with assertion in Ubuntu 18.04 server, seems to be a fixed issue in up-stream

[LGB [Gábor Lénárt]]

# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.1 LTS
Release: 18.04
Codename: bionic
# journalctl | fgrep assertion
Nov 11 01:34:14 logserver syslog-ng[11733]: ERROR:../../lib/logpipe.h:314:log_pipe_queue: assertion failed: ((s->flags & PIF_INITIALIZED) != 0)
Nov 12 15:09:06 logserver syslog-ng[15136]: ERROR:../../lib/logpipe.h:314:log_pipe_queue: assertion failed: ((s->flags & PIF_INITIALIZED) != 0)
Nov 14 02:15:32 logserver syslog-ng[18020]: ERROR:../../lib/logpipe.h:314:log_pipe_queue: assertion failed: ((s->flags & PIF_INITIALIZED) != 0)
Nov 15 00:21:03 logserver syslog-ng[13852]: ERROR:../../lib/logpipe.h:314:log_pipe_queue: assertion failed: ((s->flags & PIF_INITIALIZED) != 0)
Nov 16 05:00:04 logserver syslog-ng[28124]: ERROR:../../lib/logpipe.h:314:log_pipe_queue: assertion failed: ((s->flags & PIF_INITIALIZED) != 0)
# dpkg -s syslog-ng | grep -i versi
Version: 3.13.2-3

I have the following assertion from syslog-ng almost every day once. Since it's a log server for many other servers, it's not so great to have this problem. I've tried to google a bit, and found this:

https://github.com/balabit/syslog-ng/pull/1858

So it seems the upstream's patch against exactly this problem, just a small quote:

"File destination (time-reap) crash under immense load. The race is in the file destination between our queueing mechanism (affile_dd_queue()) and time-reap() (affile_dd_reap_writer()). Basically, time-reap() could deinitialize the writer while the queue (and the writer) was being used."

A bug report of the syslog-ng team:

https://github.com/balabit/syslog-ng/issues/1557

So, they seems to suggest to upgrade to 3.16.1 version of syslog-ng.

However, in Ubuntu 18.04 LTS, the syslog-ng is only version 3.13.2. Since it's an LTS version, I would suggest, to backport this patch, or better upgrade to newer syslog-ng version.

It seems to be a race condition bug, affecting any users with greater load on logging, it seems, according to their descriptions.

Thanks!