[ubuntu] leaking memory

[background]
1. upgrade from Ubuntu 12.04 LTS to 14.04 LTS

[problem]
1. after command ‘sudo’, the following error messages showed up.

[solution]
1. remove the obsolete apps like this. –> it did not work.

2. oh, no! it’s a bug!
https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/1274680
3. workaround

[reference]
1. http://ubuntuforums.org/showthread.php?t=2214042
2. http://www.spinics.net/lists/samba/msg115086.html