$ su
Password:
su: Authentication failure
解决此问题输入如下命令：
$ sudo passwd root
然后按照提示输入密码， 等到提示： passwd: password updated successfully
再重新试su命令
$ su
Password:
su: Authentication failure
解决此问题输入如下命令：
$ sudo passwd root
然后按照提示输入密码， 等到提示： passwd: password updated successfully
再重新试su命令
![The character device /dev/vboxdrv does not exist.Kali下Virtualbox出现The character device /dev/vboxdrv does not exist问题的解决[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)