VirtualBox 5.0.4: Cannot create device /dev/vboxdrv with major 10 and minor 57u 58

[Dâniel Fraga]

This is what I get when I try: /etc/init.d/vboxdrv setup

Stopping VirtualBox kernel modules ...done. Removing old VirtualBox pci kernel module ...done. Removing old VirtualBox netadp kernel module ...done. Removing old VirtualBox netflt kernel module ...done. Removing old VirtualBox kernel module ...done. Recompiling VirtualBox kernel modules ...done. Starting VirtualBox kernel modulessleep: invalid time interval `.2'

...failed!

(Cannot create device /dev/vboxdrv with major 10 and minor 57u

58)

Any hints?

I'm using VirtualBox-5.0.4-102546-Linux_amd64.run (generic). The log seems fine, the kernel modulo is compiled properly. I can even load it:

modprobe vboxdrv

So any hints? Thanks.

[Frank Mehnert]

Would be great to know the Linux distribution you are using and if the kernel you used is self-compiled or you are using the kernel from the distribution.

[Frank Mehnert]

Would be great to know the Linux distribution you are using and if the kernel you used is self-compiled or you are using the kernel from the distribution.

[Dâniel Fraga]

I'm using Linux from scratch and yes, the kernel is self-compiled.

I think the problem is with this line from vboxdrv:

sed -n 's;\([0-9]\+\) vboxdrv;\1;p' /proc/misc

 57u
 58

The "u" after 57 is wrong, right?

Take a look at /proc/misc:

 57 vboxdrvu
 58 vboxdrv
200 tun
232 kvm
235 autofs
184 microcode
 59 memory_bandwidth
 60 network_throughput
 61 network_latency
 62 cpu_dma_latency
227 mcelog
228 hpet
 63 vga_arbiter

[Dâniel Fraga]

Replying to frank:

Would be great to know the Linux distribution you are using and if the kernel you used is self-compiled or you are using the kernel from the distribution.

Ok Frank, the solution is to change the following line in /etc/init.d/vboxdrv:

MINOR=`sed -n 's;\([0-9]\+\) vboxdrv;\1;p' /proc/misc`

and add a "$" at the end of "vboxdrv", so it doesn't get confused by vboxdrvu returning 2 numbers:

MINOR=`sed -n 's;\([0-9]\+\) vboxdrv$;\1;p' /proc/misc`

That fixed.

[Technologov]

Why is this problem affects only Linux-From-Scratch, but none of the mainstream distros ? (SUSE/Red Hat/Debian/Ubunbu)

What is so special about LFS ? And why "vboxdrvu" gets created ?

[Frank Mehnert]

Dâniel, thanks for the suggestion. I think this code path is normally not used because as soon as the vboxdrv module is loaded, both /dev/vboxdrv and vboxdrvu are created automatically. Not sure why this doesn't work for you. Anyway, I've committed a similar change which will be part of the next maintenance release.

To answer the other question: /dev/vboxdrvu is another interface which allows non-hardened processes (e.g. VBoxSVC) to access a tiny part of the kernel interface. It's mainly used to detect CPU features like the availability of nested paging (which can only be detected from ring 0).

[Frank Mehnert]

Fix is part of 5.0.6.

[Dâniel Fraga]

Replying to Technologov:

Why is this problem affects only Linux-From-Scratch, but none of the mainstream distros ? (SUSE/Red Hat/Debian/Ubunbu)

What is so special about LFS ? And why "vboxdrvu" gets created ?

Well, I don't know, but /proc/misc output is pretty standard, isn't? If I get the vboxdrvu, then it should be considered.

But I see it got fixed in the last version. Thank you Frank.