Comment 5 for bug 1918410

Okay adding the suggested rule

works for me. So it would seem dhclient is treating denied access to comm as a fatal error.

Interestingly I also had it throw a rejection for capability sys_module

[ 1645.480546] audit: type=1400 audit(1616847221.859:73): apparmor="DENIED" operation="capable" profile="/{,usr/}sbin/dhclient" pid=3380 comm="dhclient" capability=16 capname="sys_module"

which should not generally be required anymore. See https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1759032