Bug 241269

Summary:	syslogd fails to log anything if there is a unicode character in the hostname of a machine
Product:	Base System	Reporter:	Sverre <sverre.eldoy>
Component:	misc	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	New ---
Severity:	Affects Some People	CC:	cem, emaste, freebsd, yuripv
Priority:	---
Version:	12.0-RELEASE
Hardware:	Any
OS:	Any

Description Sverre 2019-10-15 13:59:56 UTC

I have this machine that has a single unicode character (a monkey) as it's hostname.. In the past this has worked quite well but now syslogd doesn't log anything at all. I am not 100% sure when the regression happened, but I suspect it was around February this year. 

Turning on the debug-flag I see the screen filling up with:
Failed to parse HOSTNAME from and then every single line of output that should have been logged. 

I suspect this might happen to anybody that has a funky character in their hostname.

Comment 1 Yuri Pankov freebsd_committer

2019-10-17 06:19:02 UTC

Which exactly character (code) is the problem?

Comment 2 Sverre 2019-10-18 17:13:32 UTC

(In reply to Yuri Pankov from comment #1)
🐒

Comment 3 Sverre 2019-10-18 17:14:03 UTC

(In reply to Sverre from comment #2)
The hostname is 🐒.domain.blah

Comment 4 Sverre 2019-11-01 14:47:43 UTC

Actually it seems that it's enough to have some emoji char in your hostname - it doesn't have to be all emoji... so awef🐒awef.domain.blah will also make syslogd fail to log... I think it's the part where it strips out "dangerous characters" that is the culprit,.. Compiling a version without that check now to see if that works.

Comment 5 Sverre 2019-11-01 15:45:43 UTC

It doesn't actually have to be an emoji either.. ℬ, ⨊, ... even the norwegian letters like å,æ,ø makes it fail.. and the swedish variants ä, ö .. It's a nice way to disable all logging if you got root on a box: just switch your hostname to something that has a  weird character in it and there is basically no trace of anything you do on it.