I think its less a question of the technical feasibility, and more of an issue that we, as users, don't want more closed-source blobs in our kernels. Meanwhile, the publishers insist that they can't open-source their anti-cheat code; Their idea being that if we know what's in it, it will be easier to bypass.

Basically, one distro or a few(at most) may get anti-cheat integrated one day(like, say, SteamOS), but it will likely never be in your standard Linux kernel.

They could go the route of kernel modules, I would think, but for whatever reason, we're still having this conversation.

Absolutely nothing prevents somebody from writing a kernel level anticheat on Linux.

Users would throw a fit, and it would be way easier to bypass, but it certainly could be made.

One way I can imagine it being some certified Linux kernel versions that are accepted and worked together with anticheat creators. That way Valve could use the Kernel in Steam Deck or SteamOS, so any game works out of the box. And other distribution users can just install this Kernel too, if their distributions provide it.

Anyone who don't want to have Kernel level anticheat systems enabled on their system, do not need to install the Kernel. Therefore they are secure against it. But for anyone else who wants it, they can. At least this option would be a compromise.

AFAIK Microsoft have plans to block kernel level anti-cheat on Windows. After the CrowdSec issues last year, they're rethinking which types of programs should even be allowed to run in kernel space.

Edit: I was wrong. They actually want to increase what can be done in user mode, to reduce reliance on kernel mode code.

Meanwhile in indie land, I just tried to cheat my way through a Chapter 3 minigame in Deltarune, and Toby Fox himself showed up in his dogsona to blow up the game and make me start the minigame over.

This is the extent to which anti-cheat measures should go.

You can add your own signing keys to the UEFI and boot an modified bootloader and Kernel that you have signed yourself.
So yes, it is possible to "lie"

For such a locked down system, akin to game consoles or smartphones, would be needed. And even those get jail broken and manipulated, so "total security" on there is not complete but easier to check and ensure.
Another way to make sure that the code is not manipulated would be to put all those games into the cloud and have every player only play via streaming. All the code would then run on secured, locked down and verified machines.

kernel level anti cheat is malware

abandon ranked, return to private lobbies

Linux secure boot was a little weird last I checked. The kernel and modules don't need to be secure boot signed. Most distros can use shim to pass secure boot and then take over the secure boot process.

There are dkms kernel modules that are user compiled. These are signed using a machine owner key. So the machine owner could for sure compile their own malicious version and still be in a secure boot context.

Another technique that helps is to limit the amount of information shared with clients to need to know info. This can be computationally intensive server-side and hard to get right .. but it can help in many cases. There are evolving techniques to do this.

In FPS games, there can also be streaming input validation. eg. Accurate fire requires the right sequence of events and/or is used for cheat detection. At the point where cheats have to emulate human behaviour, with human-like reaction times, the value of cheating drops.

That's the advanced stuff. Many games don't even check whether people are running around out of bounds, flying through the air etc. Known bugs and map exploits don't get fixed for years.

TBH I'm not sure wider adoption would worsen things ? Gaming distros would probably ship bullshit anticheat modules by default while the others would not, or at most provide some documentation on how to opt in.

I think it's quite similar to the situation with NVIDIA proprietary drivers? (I don't own a graphics card so I'm not super aware on this topic)

I surely hope they never will, no user program should ever be allowed to run at kernel level, that's what malware does.

I personally avoid those kind of games, but those who won't can dual-boot.

On one side, I'm one of those glad for people coming to Linux because Linux is truly fantastic and it can make your life easier on many things, I'm happy for them.

On the other side, I share your concerns, because everything that gets adopted by the masses is inevitably subject to enshittification, I would never want that to happen to Linux.

We should find a sweet middle-point tho I have no idea what that would be.

I think the more people who aren't using corporate operating systems, the better.

I'm firmly against Microsoft, Red Hat, and Ubuntu.

Every IT-literate person fights kernel-lvl malware disguising as games with everything they got.

Since Linux has a high percentage of those, I hope those "solutions" will never spread

It's relatively trivial, you just need to write a kernel module. You'd just need/want to make it gpl so everything it does is fully audited and transparent. That's not a problem, is it? Right?

From a technical standpoint, you could argue that someone could create a fork of the kernel that spoofs the interface that the anticheat uses to make it ignore things. You can, of course, also do something similar in Windows, but security theatre never let practicality get in the way.

Short answer: no

Long answer: only the most important things should even have such low-level access to the system. A fucking game is not in that category. Nooooooo