Host - Win10, Virtualbox 6.1.22 r144080
Whonix - Whonix XFCE 15.0.1.7.3
First start is ok, clipboard sharing, screen resizing, etc - everything works well.
But installing updates seem to break guest additions
Here is a dmesg from fully updated Whonix Gateway (the issue also affects workstation)
[ 44.406038] vboxvideo: loading version 6.1.22 r144080
[ 44.463874] 08:18:11.454133 main VBoxService 6.1.22 r144080 (verbosity: 0) linux.amd64 (Apr 28 2021 18:43:39) release log
08:18:11.4541
[ 44.464101] 08:18:11.454779 main OS Product: Linux
[ 44.464356] 08:18:11.454995 main OS Release: 4.19.0-17-amd64
[ 44.464719] 08:18:11.455248 main OS Version: #1 SMP Debian 4.19.194-2 (2021-06-21)
[ 44.465310] 08:18:11.455621 main Executable: /opt/VBoxGuestAdditions-6.1.22/sbin/VBoxService
08:18:11.455622 main Process ID: 9382
[ 44.467022] 08:18:11.457574 main 6.1.22 r144080 started. Verbose level = 0
[ 44.468705] 08:18:11.459188 main vbglR3GuestCtrlDetectPeekGetCancelSupport: Supported (#1)
[ 44.471882] 08:18:11.462243 main Error: Failed to become guest control master: VERR_VERSION_MISMATCH
[ 44.472477] 08:18:11.462910 main Error: Service 'control' failed to initialize: VERR_VERSION_MISMATCH
[ 44.472830] 08:18:11.463442 main Session 0 is about to close ...
[ 44.473103] 08:18:11.463723 main Stopping all guest processes ...
[ 44.473354] 08:18:11.464007 main Closing all guest files ...
[ 44.473963] 08:18:11.464682 main Ended.
[ 45.331761] Service: Shared Clipboard
[ 45.334355] Service: Host Version Check
[ 45.337093] Service: Seamless
[ 45.339955] Service: Drag and Drop (DnD)
[ 45.342929] Service: Display SVGA X11
[ 45.344141] Worker loop running
[ 45.346587] Proxy window=8388609, root window=940 ...
[ 45.346845] Started
[ 45.346916] 6.1.22r144080
[ 45.348396] VMWARE's ctrl extension is available. Major Opcode is 128.
[ 45.351440] Failed to register resizing support, rc=VERR_INVALID_FUNCTION
[ 45.583402] Service: Shared Clipboard
[ 45.634858] Service: Host Version Check
[ 45.647659] Service: Seamless
[ 45.666322] Service: Drag and Drop (DnD)
[ 45.677994] Service: Display SVGA X11
[ 45.945545] Denying userspace vmm call type 0x000051
[ 45.945827] Failed to get display change request, rc=VERR_ACCESS_DENIED
This is likely because of the kernel upgrade, for some reason guest additions are only built for the current kernel.