[Firefox] freezes the whole OS

Distribution

Mint 20.1

Package version

4.8.6

Graphics hardware in use

GTX 1060 Max-Q 3GB (laptop)

Frequency

Always

Bug description

Last available Firefox version 115.0+linuxmint1+una or 115.0+build2-0ubuntu0.20.04.3 makes Linux Mint 20.1 with Cinnamon 4.8.6 completely freeze, only the mouse pointer may still continue to move but keyboard inputs are all ignored. The PC has to be shutdown in order to recover from this.

CPU: Intel(R) Core(TM) i5-7300HQ CPU @ 2.50GHz
Integrated GPU: Mesa Intel(R) HD Graphics 630 (KBL GT2)
GPU: GTX 1060 Max-Q 3GB (laptop)

The bug arises with both the following kernels: x86_64 Linux 5.4.0-152-generic and 5.4.0-153-generic.

Steps to reproduce

Watch a video on Youtube using Firefox, wait a bit, and eventually delete the history and temp files.
Upon closing Firefox, its processes are still running and visible in the System Monitor. I tried killing them from there, it did work once but freezed the OS another time. Also, trying to shutdown the system while Firefox process are still running do produce the bug too...

Expected behavior

Linux Mint freezes, keyboard input are ignored, but the mouse pointer is still moving.

Additional information

No response

The report names no files, tests, or Cinnamon entry points. Start by reproducing the freeze with Firefox while watching a YouTube video, deleting history and temporary files, then closing Firefox or shutting down on Linux Mint 20.1 with the listed kernels and hardware. Done requires identifying a reproducible cause and verifying that the system no longer freezes.