VirtualBoxで`VirtualBox is complaining that the kernel module is not loaded`

Ubuntu 14.04LTSホスト上で

$ vagrant up
The provider 'virtualbox' that was requested to back the machine
'default' is reporting that it isn't usable on this system. The
reason is shown below:

VirtualBox is complaining that the kernel module is not loaded. Please
run `VBoxManage --version` or open the VirtualBox GUI to see the error
message which should contain instructions on how to fix this error.

エラーメッセージ見てみろというので確認

$ VBoxManage --version
WARNING: The vboxdrv kernel module is not loaded. Either there is no module
         available for the current kernel (3.19.0-49-generic) or it failed to
         load. Please recompile the kernel module and install it by

           sudo /sbin/rcvboxdrv setup

         You will not be able to start VMs until this problem is fixed.
5.0.14r105127

（VirtualBoxの？）recompileをしろというので、

$ sudo /sbin/rcvboxdrv setup
Bad argument setup

おい！どうすんだよ！

...ってことでaskUbuntu

どうやらsudo /usr/lib/virtualbox/vboxdrv.sh setupを使うらしい。

$ VBoxManage --version
5.0.14r105127

直った。
これってKernelのUpdateの度に必要なんだっけ？...