I was updating the OS today (security patches), when I found something strange in the syslog:
apparmor="DENIED" operation="signal" profile="/usr/sbin/cupsd" pid=2483 comm="cupsd" requested_mask="send" denied_mask="send" signal=term peer="unconfined"
It appeared in the syslog 5 times.
I never saw this log, so I started to look about it, but no success. the only thing I know is that cupsd is something about printer (something that I never used with Ubuntu).
So, I also took a look into the /log/cups/access_log
and I found this (looking at the timestamp, this log came 1 second before the log from the syslog):
localhost - - [07/Jul/2015:11:49:50 -0300] "POST / HTTP/1.1" 200 3695675 CUPS-Get-PPDs -
So, I never had any DENIED thing from apparmor. Anyone knows why this happenned? Also note that I never had to use a printer with Ubuntu.
Thank you guys for helping me.
EDIT: Just noticed that in the same day that I downloaded the updates, I also installed updates for the cups
. Maybe that's why it had the DENIED log?