vboxsf in virtualbox-ose-guest-dkms is getting in conflict with a "default" vboxguest module

[aaFn]

Is this a new report?

Yes

System Info

Void 6.12.63_1 x86_64 GenuineIntel/KVM uptodate rFF

Package(s) Affected

virtualbox-ose-guest-dkms

Does a report exist for this bug with the project's home (upstream) and/or another distro?

No response

Expected behaviour

In a void-linux guest, under Windows host with Virtualbox 7.2.4 (but the problem is there since long ..!) and after installation of virtualbox-ose-guest and virtualbox-ose-guest-dkms through xbps-install:

vboxsf should load on boot, and it should be possible to access Shared folders from the Virtualbox host after issuing
sudo mount.vboxsf Shared_files /media/share

Actual behaviour

On VM boot after installation of virtualbox-ose-guest and virtualbox-ose-guest-dkms through xbps-install, modprobe vboxsf fails, with the following messages:

Error on boot screen:
modprobe: ERROR: could not insert 'vboxsf': Unknown symbol in module, or unknown parameter (see dmesg)

DETAILS
Errors in dmesg:

[    1.682514] vboxsf: loading out-of-tree module taints kernel.
[    1.682517] vboxsf: module verification failed: signature and/or required key missing - tainting kernel
[    1.682556] vboxsf: Unknown symbol VBoxGuest_RTLogBackdoorPrintf (err -2)
[    1.682568] vboxsf: Unknown symbol VBoxGuestIDC (err -2)
[    1.682577] vboxsf: Unknown symbol VBoxGuest_RTSemFastMutexRequest (err -2)
[    1.682584] vboxsf: Unknown symbol VBoxGuest_RTSemFastMutexRelease (err -2)
[    1.682589] vboxsf: Unknown symbol VBoxGuest_RTStrNLen (err -2)
[    1.682593] vboxsf: Unknown symbol VBoxGuest_RTR0MemObjFree (err -2)
[    1.682599] vboxsf: Unknown symbol VBoxGuest_RTLogRelGetDefaultInstanceEx (err -2)
[    1.682604] vboxsf: Unknown symbol VBoxGuest_RTR0MemObjAddress (err -2)
[    1.682609] vboxsf: Unknown symbol VBoxGuest_RTStrCopy (err -2)
[    1.682613] vboxsf: Unknown symbol VBoxGuest_RTErrConvertToErrno (err -2)
[    1.682623] vboxsf: Unknown symbol VBoxGuest_RTSemFastMutexCreate (err -2)
[    1.682627] vboxsf: Unknown symbol VBoxGuest_RTSemFastMutexDestroy (err -2)
[    1.682632] vboxsf: Unknown symbol VBoxGuest_RTR0MemObjAllocContTag (err -2)
[    1.682639] vboxsf: Unknown symbol VBoxGuest_RTSemMutexRelease (err -2)
[    1.682644] vboxsf: Unknown symbol VBoxGuest_rtR0MemObjLinuxVirtToPage (err -2)
[    1.682649] vboxsf: Unknown symbol VBoxGuest_RTAssertShouldPanic (err -2)
[    1.682655] vboxsf: Unknown symbol VBoxGuest_RTLogLoggerEx (err -2)
[    1.682662] vboxsf: Unknown symbol VBoxGuest_RTSemMutexRequest (err -2)
[    1.682666] vboxsf: Unknown symbol VBoxGuest_RTSemMutexCreate (err -2)
...

All modules are good in /usr/lib/modules/6.12.63_1/updates/, they reflect the ones in /var/lib/dkms/virtualbox-ose-guest/7.2.4/6.12.63_1/x86_64/module/

lsmod | grep vbox shows:

vboxvideo              65536  0
drm_ttm_helper         16384  3 vmwgfx,vboxvideo
ttm                   106496  3 vmwgfx,vboxvideo,drm_ttm_helper
drm_kms_helper        241664  3 vmwgfx,vboxvideo,drm_ttm_helper
drm                   753664  7 vmwgfx,drm_kms_helper,vboxvideo,drm_ttm_helper,ttm
vboxguest              53248  4

However, 53248 is a bad size for the 7.2.4 vboxguest module !! (see below, the good size is 491520, cf. alternative 3)

Worse: before the installation of virtualbox-ose-guest and virtualbox-ose-guest-dkms, the same command shows

vboxguest              53248  0

meaning that a "default" vboxguest is already loaded from somewhere.

Alternative test 1 : as a verification during another test that I made with another fresh new VM instance, I removed all vboxguest modules from the filesystem just after first start (I used find . -name vbox* from / to find them and remove them), without installing these 2 virtualbox-ose-guest packages of course, and rebooted ...
=> vboxguest is still showing again in lsmod !! .. not sure where it comes from :-(

Alternative test 2 : during yet another test that I made with again another fresh new VM instance, I installed only virtualbox-ose-guest, but not virtualbox-ose-guest-dkms.
Then, after reboot, the lsmod command shows:

vboxvideo              36864  0
drm_vram_helper        28672  1 vboxvideo
vboxsf                 45056  0
drm_ttm_helper         16384  4 vmwgfx,drm_vram_helper,vboxvideo
drm_kms_helper        241664  4 vmwgfx,drm_vram_helper,vboxvideo,drm_ttm_helper
drm                   753664  8 vmwgfx,drm_kms_helper,drm_vram_helper,vboxvideo,drm_ttm_helper,ttm
vboxguest              53248  1 vboxsf

vboxsf works fine .. however, the bidirectional copy/paste on clipboard with the host is not working :-(
I have to force execute manually /bin/VBoxClient-all for that to work (while in the main case above, the bidirectional copy/paste works).
Note also the size of vboxvideo, different from the main case above, and the size of vboxsf = 45056, which is much smaller than the 7.2.4 vboxsf (106496, cf. alternative 3).

Alternative test 3 : during yet another test that I made with again another fresh new VM instance, I removed vboxguest:

modprobe -r vboxguest

and verified that it is not showing anymore in lsmod.
Then I installed virtualbox-ose-guest and virtualbox-ose-guest-dkms.
Then as root:

modprobe vboxguest
modprobe vboxvideo
modprobe vboxsf

This works fine !!
The lsmod command shows:

vboxsf                106496  0
vboxvideo              65536  0
vboxguest             491520  1 vboxsf
drm_ttm_helper         16384  3 vmwgfx,vboxvideo
ttm                   106496  3 vmwgfx,vboxvideo,drm_ttm_helper
drm_kms_helper        241664  3 vmwgfx,vboxvideo,drm_ttm_helper
drm                   753664  7 vmwgfx,drm_kms_helper,vboxvideo,drm_ttm_helper,ttm

and it is possible to connect the shared folders from the host.
Note the vboxguest, vboxvideo and vboxsf sizes ..
However ... after a simple reboot ... this is broken again, with vboxsf refusing to load, errors on unknown symbols, and lsmod showing again a vboxguest module with size = 53248 !!

Steps to reproduce

Create a new Linux VM in VirtualBox, 16 GB disk, not UEFI, 1 proc, 1 GB RAM, no PAE/NX, Nested paging on, VMSVGA, 64 MB video RAM, no 3D acceleration ..
Attach the "Live-CD" https://repo-default.voidlinux.org/live/current/void-live-x86_64-20250202-xfce.iso

Start VM, and run void-installer install, to create the fresh new VM.
No special configuration on the installer.
Reboot, after removing the Live-CD ISO attachment.
Then do once as root "xbps-install -Su".
And reboot again.

On that next boot, vboxsf will fail on boot load by DKMS, as explained in the "Actual behavior" part.
Note: alternative scenarios 1, 2 and 3 also start from that point.

[aaFn]

In very short, it seems that there is a "default" vboxguest loaded from somewhere (unknown) at boot time, with a very small size so not corresponding to 7.2.4, which is conflicting with the 7.2.4 vboxguest and preventing it to load.
Which then makes the 7.2.4 vboxsf fail ..

Could that be coming from initramfs or vmlinuz ??

[aaFn]

Workaround until there is a fix so that things work well by default:

Create a file 01-workaround-vboxguest.sh in /etc/runit/core-services
with content:

# Fix for wrong vboxguest being loaded by default ..

modprobe -r vboxguest

Reboot ..
With that, all is ok, the proper vboxguest is loaded by /usr/lib/modules-load.d/virtualbox-guest.conf at boot time.
Then, vboxsf also loads ok, and lsmod | grep vbox returns the right sizes:

vboxvideo              65536  0
vboxsf                106496  0
vboxguest             491520  5 vboxsf
drm_ttm_helper         16384  3 vmwgfx,vboxvideo
ttm                   106496  3 vmwgfx,vboxvideo,drm_ttm_helper
drm_kms_helper        241664  3 vmwgfx,vboxvideo,drm_ttm_helper
drm                   753664  7 vmwgfx,drm_kms_helper,vboxvideo,drm_ttm_helper,ttm