tmpreaper --runtime limit/exit does not stop its children

[Neil Harkins]

Hello, we see tmpreaper children still running after its parent exits due to
hitting the --runtime arg limit, but expect them to exit along with the parent:

CMD=/usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15d /tmp/
DURATION=300.06secs
OUTPUT=
error: run time exceeded!
This may be indicative of an attack to use tmpreaper to remove critical files;
or the directories to clean up are excessive large and/or messed up.
Please investigate.

jenkins01$ ps xao pid,ppid,pgid,sid,cmd | grep tmpreaper
 17797 1 17635 17635 /usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15 /tmp/
 56784 17797 17635 17635 /usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15 /tmp/
 84772 56784 17635 17635 /usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15 /tmp/
 84775 84772 17635 17635 /usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15 /tmp/
 84777 84775 17635 17635 /usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15 /tmp/
 84779 84777 17635 17635 /usr/sbin/tmpreaper --protect hsperfdata*/* --runtime=300 --ctime 15 /tmp/

jenkins01$ lsb_release -rd
Description: Ubuntu 12.04.5 LTS
Release: 12.04

jenkins01$ apt-cache policy tmpreaper
tmpreaper:
  Installed: 1.6.13+nmu1