vboxdrv does not exist. after kernel installation

Question

I've installed kernel 4.12.0-041200rc4-generic, and since then when i open Virtual Box i get this

root@machine:~# virtualbox 
WARNING: The character device /dev/vboxdrv does not exist.
     Please install the virtualbox-dkms package and the appropriate
     headers, most likely linux-headers-generic.

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

Tried to fix it and got this:

root@machine:~# aptitude install linux-headers-generic virtualbox-dkms 
linux-headers-generic is already installed at the requested version (4.4.0.78.84)
virtualbox-dkms is already installed at the requested version (5.0.40-dfsg-0ubuntu1.16.04.1)
linux-headers-generic is already installed at the requested version (4.4.0.78.84)
virtualbox-dkms is already installed at the requested version (5.0.40-dfsg-0ubuntu1.16.04.1)
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.

Guessed i needed to install linux-headers-generic version 4.12

root@machine:~# aptitude install linux-headers-$(uname -r)
linux-headers-4.12.0-041200rc4-generic is already installed at the requested version (4.12.0-041200rc4.201706042031)
linux-headers-4.12.0-041200rc4-generic is already installed at the requested version (4.12.0-041200rc4.201706042031)
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.