*System Information**
Operating system: GENTOO Linux (updated daily)
Graphics card: NVIDIA Corporation TU106 [GeForce RTX 2060 SUPER] (rev a1)
Graphics card driver: x11-drivers/nvidia-drivers-470.74

Blender Version
Broken: blender-3.0.0-alpha+master.886196b88817-linux.x86_64-release
Worked: blender-3.0.0-alpha+master.18959c502d62-linux.x86_64-release

Short description of error
Trying to edit particle hair locks blender hard.

Exact steps for others to reproduce the error
Load the file provided. Go Particle Edit Mode and switch to "comb". Try to comb the hair.
The "working" version above is only "kind of working": There is no lock happening. That is the working part.
But the brusch seems not to be able to move accross certain invisible boundaries. May be not the process hangs,
but the part of the software, which handles cursor/brush movements becomes locked?
CPU load is zero, so no endless loop or something like that is involved. "Feels" more like a deadlock.
Only killing the according process can end this. The graphics system as such is not locked. There is no debug output on the console.