Arch Linux

archtom

Member

Registered: 2011-05-04

Posts: 58

virtualbox shared folder not mounting (linux-grsec)

Hey,

I´m using archlinux 64 bit as a linux guest on an osx host in virtualbox (4.3.28) with all packages up to date. I managed to install the grsecurity hardened linux-grsec kernel. Unfortunately it brought a lot of work to be done afterwards...

I installed the virtualbox-guest-dkms and build the guest modules, got them to load and started VBoxClient-all.

Everything seems to work fine except of the mounting of the shared folder. It worked with the same settings before installing the grsec kernel. The shared folder is set to automount and nothing else is configured in archlinux.

I did not change anything at the default grsec and pax preferences of the kernel.

After starting the system (the shared folder is called "down") /media/sf_down ends up empty.

When running

VBoxService -f

as root I get the following error:

...
00:00:00.006995 automount Error: VBoxServiceAutoMountWorker: Could not mount shared folder "down" to "/media/sf_down": Protocol error (71)
...

When running

VBoxService -fvvv

it is getting more concrete:

...
00:00:00.010347 automount VBoxServiceAutoMountWorker: Shared folder mount prefix set to "sf_"
00:00:00.010443 automount VBoxServiceAutoMountWorker: Got 1 shared folder mappings
00:00:00.010795 automount VBoxServiceAutoMountWorker: Connecting share 1 (down) ...
00:00:00.012338 automount VBoxServiceAutoMountWorker: Messed up share name, re-trying ...
00:00:00.012610 automount VBoxServiceAutoMountWorker: Re-trying with old mounting structure ...
00:00:00.013087 automount Error: VBoxServiceAutoMountWorker: Could not mount shared folder "down" to "/media/sf_down": Protocol error (71)
00:00:00.013184 automount VBoxServiceAutoMountWorker: Mounting returned with rc=VERR_NET_PROTOCOL_ERROR
...

When trying to mount the share manually the same error persists.

sudo mount -t vboxsf -o uid=1000,gid=1000 down /media/sf_down

/sbin/mount.vboxsf: mounting failed with the error: Protocol error

And yes, my user "tom" is in the vboxsf group and trying with root doesn`t work either.

I already tried changing the share name and I already tried deleting the share and re-adding it.

I googled a lot but couldn`t find an answer and I´m not sure if it`s just a setting that has to be done or anything else completely.

If you need any other info just let me know.

Thanks for every help.

fhdk

Member

Registered: 2015-07-17

Posts: 2

Re: virtualbox shared folder not mounting (linux-grsec)

Stumpled upon this while searching for the exact same issue.

Thought I would share what I did to resolve it.

    $ ls -la /media/
    ls: cannot open directory /media/: Permission denied

    $ ls -la /media/sf_xxx/
    ls: cannot open directory /media/sf_xxx/: Permission denied

    $ sudo ls -la /media/
    totalt 12
    drwxr-x---   3 root   root    4096 17 jul 18:16 .
    drwxr-xr-x 18 xxx   users  4096 17 jul 18:16 ..
    drwxrwx---  2 root  vboxsf 4096 17 jul 18:16 xxx

Though I should have the right to read the folder /media I am denied as the above show.

By tweaking the folder /media

    $ sudo chown root:users /media

Checking group membership

    $ cat /etc/group | grep vboxsf
    vboxsf:x:109:xxx

Checking uid:gid

    $ cat /etc/passwd | grep xxx
    xxx:x:1000:100:,,,,:/home/xxx:/bin/bash

Manual mount

    $ sudo mount.vboxsf -o uid=1000,gid=100 xxx /media/sf_xxx
    $ ls -la /media/
    total 8
    drwxr-x---   3 root users 4096 Jul 17 18:16 .
    drwxr-xr-x 18 xxx  users 4096 Jul 17 18:16 ..
    drwxr-xr-x   1 xxx  users 1564 Jul 17 16:38 sf_xxx

    $ la -la /media/sf_xxx/
    total 588
    drwxr-xr-x 1 xxx  users   1564 Jul 17 16:38 .
    drwxr-x--- 3 root users   4096 Jul 17 18:16 ..
    drwxr-xr-x 1 xxx  users       68 Jan 21  2013 Applications
    drwxr-xr-x 1 xxx  users     102 Jan 21  2013 Applications (Parallels)
    drwx------ 1 xxx  users   2244 Jul 17 12:27 Desktop
    drwx------ 1 xxx  users    544 Jul 13 07:41 Documents
    drwx------ 1 xxx  users    442 Jul 17 12:10 Downloads
    drwx------ 1 xxx  users    374 Aug 18  2014 .dropbox
    drwx------ 1 xxx  users    238 Aug 18  2014 Dropbox
    drwx------ 1 xxx  users   1700 Jul 17 19:23 Library
    drwx------ 1 xxx  users    204 Jul 25  2013 Movies
    drwx------ 1 xxx  users    170 Jul 18  2013 Music
    drwx------ 1 xxx  users    204 Jul  1 10:57 Pictures
    drwxr-xr-x 1 xxx users    136 Jan 21  2013 Public
    drwxr-xr-x 1 xxx users    102 Jul 17 16:38 VirtualBox VMs

Now I am able to mount the share.

The share is still not automounting possibly due to insufficient permissions

Last edited by fhdk (2015-07-17 17:59:18)