Crash when VM has mouse integration enabled and screen scaling

[SteveE]

I'm experiencing a repeatable crash using Virtualbox on an Ubuntu laptop using the default Gnome/Wayland desktop with a HiDPI screen.

Virtualbox 6.0.15, also tried latest 6.5
Ubuntu 19.10

I've tried with guests using Ubuntu 19.04 & 19.10, and Kubuntu 19.10, with the same results. Guests all have the matching guest editions versions installed, but I also had the same issue during Live CD installation and therefore no guest additions installed.

Laptop has screen scaling enabled in Gnome at 2x.

NVidia graphics chip using the v435 drivers.

If I have Virtualbox screen scaling for the VM set, and I have mouse integration enabled, the VM will come up normally, but as soon as the mouse pointer enters the VMs window, the whole laptop screen freezes. Sometimes it will terminate the current host machines Gnome session and put me back to the login prompt, other times it just freezes permanently requiring a forced power cycle. If I disable mouse integration it works fine. If I remove guest screen scaling, and leave mouse integration enabled, it works fine.

I was running Kubuntu 19.10 on this laptop, with KDE screen scaling enabled, Virtualbox screen scaling enabled, and mouse integration, and did not encounter this issue. I then installed Gnome on the machine (still with Kubuntu base), and the issue was encountered. I've since re-installed the machine with Ubuntu 19.10, which didn't have any change on this crash.

I tried the Virtualbox 6.5 latest version, which exhibited the same behaviour.

I've left my VMs with Virtualbox screen scaling off, and used the VM desktops own screen scaling to compensate, which is working fine (with mouse integration), so it's no longer an issue for me, but I'm logging this here in case anyone else comes across this, and maybe the devs might like to look into this as a bug.

[mpack]

I tried the Virtualbox 6.5 latest version, which exhibited the same behaviour.

Uh, no such version exists, nor will for a few years I expect.

Please provide a VM log file. With the VM fully shut down, right click it in the GUI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.