ubuntu 使用sudo chmod 777 -R ./usr/lib出错

执行上述命令，再 sudo su 出错：

sudo: error in /etc/sudo.conf, line 0 while loading plugin `sudoers_policy'
sudo: /usr/lib/sudo/sudoers.so must be only be writable by owner
sudo: fatal error, unable to load plugins

解决：

su root
chmod 644 /usr/lib/sudo/sudoers.so
chown -R root /usr/lib/sudo

借鉴于https://askubuntu.com/questions/637432/sudo-comes-up-with-an-error-cannot-run-anything-as-root 感谢