I also have these messages when upgrading from Ubuntu 13.10 to 14.04.
$ grep leaked ./dist-upgrade/apt-term.log |sed 's/.*Parent PID [0-9]*: //' | sort | uniq -c 37 /bin/sh 84 /usr/sbin/grub-probe
Don't know if this is relevant but I am also affected by bug 1289977 (https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1289977)
I also have these messages when upgrading from Ubuntu 13.10 to 14.04.
$ grep leaked ./dist- upgrade/ apt-term. log |sed 's/.*Parent PID [0-9]*: //' | sort | uniq -c grub-probe
37 /bin/sh
84 /usr/sbin/
Don't know if this is relevant but I am also affected by bug 1289977 (https:/ /bugs.launchpad .net/ubuntu/ +source/ grub2/+ bug/1289977)