http://bugzilla.kernel.org/show_bug.cgi?id=12076

Remove any write access to groups and others, only keep write permission
to its owner, usually only root user.
Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>