Kernel driver not installed (rc=-1908)Esta es la solución, simple, rápida y sin reiniciar:
The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing
'/etc/init.d/vboxdrv setup'
as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.
sudo apt-get install linux-headers-`uname -r`
sudo apt-get remove dkms
sudo apt-get install dkms virtualbox-dkms
sudo modprobe vboxdrv