Re: Chrome engine based browsers (Iridium and Chromium) crashed while accessing NanoKVM USB (recognizes as USB camera + audio + uhid device emulation) device

On 2025-10-29, Martin <martingot@protonmail.com> wrote:
> First time some tests have been performed with OpenBSD 7.7 + Iridium and Chromium browsers with connected NanoKVM USB (USB camera + audio + uhid input device emulation) composite device.
>
> The same machine (OpenBSD 7.7 and 7.8 after upgrade) hosts nginx server with web page to access NanoKVM USB.
>
> By opening a link http://nanokvm.local in Iridium or Chromium browser on the same machine resolves and opens NanoKVM access page with drop down menu which asks to access camera and microphone device. Once permissions are granted "Select USB device" drop down menu has appeared with "USB3 Video" and "Select Serial Device" button to access NanoKVM USB video from remote PC where NanoKVM is connected.
>
> Once "Select Serial Device" button is pressed on the nanokvm.local web page, Iridium and Chromium browsers crash with core dump.

No idea if it will help but you could try building a kernel with a
quirk added to prevent the hid interface from attaching to uhid so that
it falls back to ugen. See UQ_BAD_HID in usb_quirks.c. Seems the serial
port device is attached behind the HID presumably so browsers can get
access to it with webhid-like mechanisms (as also used for fido keys
etc) rather than webusb. I guess you may need to disable some pledge/
unveil too.

Generally OpenBSD is not the right OS for accessing random USB hardware
from userland.

FWIW I used to take a usb hdmi capture stick (and small keyboard) for this
use-case (iirc I used vlc or ffplay with our v4l2 compat) but gave up
on it and got a jetkvm instead which I'm pretty happy with. Much easier
to handle via network than USB.