this post was submitted on 17 Oct 2023
543 points (97.9% liked)

Linux Gaming

15402 readers
345 users here now

Discussions and news about gaming on the GNU/Linux family of operating systems (including the Steam Deck). Potentially a $HOME away from home for disgruntled /r/linux_gaming denizens of the redditarian demesne.

This page can be subscribed to via RSS.

Original /r/linux_gaming pengwing by uoou.

Resources

WWW:

Discord:

IRC:

Matrix:

Telegram:

founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] chaorace@lemmy.sdf.org 16 points 1 year ago (3 children)

I'll do my best to explain:

Firstly, not all code executed on an open source OS needs to be open source. For example: Epic Anti-Cheat, which comes with a Linux-compatible mode, is fully closed source. So right off the bat we're going to put to bed the notion that somehow the platform of choice makes it easier for bad actors to pull apart and examine anticheat software.

Secondly, yes, there is a problem with cheaters being able to hide from anticheats on Linux. This is because on Windows it's relatively easy to run kernel-level code via drivers -- this is why most anticheats require admin permission to install a monitoring driver before the game will run. The anticheat is effectively rootkitting your system in order to circumvent other rootkits that may be concealing epic cheatz.

On GNU/Linux, almost all device drivers come prepackaged in the Linux kernel, so there's no direct equivalent to the Windows approach of allowing users to install third-party code into the most protected rings of the OS. It's still possible through the use of kernel modules (see NVIDIA drivers), but as evidenced by how annoying it is to use NVIDIA devices on Linux, this is a huge PITA for both the developer & the user to deal with.

So that's the rub. On Linux, anticheats just have to trust that the kernel isn't lying. This has been a perpetual thorn in the side of developers like Google, who'd really really like it if they could prove beyond a shadow of a doubt that a given Android device is not rooted (see SafetyNet). Google's solution to this has been to introduce hardware-backed attestation -- basically a special hardware chip on the device that can prove that the kernel software has not been tainted in any way.

[–] Barbarian@sh.itjust.works 7 points 1 year ago* (last edited 1 year ago)

I'm sure you agree with this, just wanted to add:

It's also true that the ease with which a program can interact with kernel level drivers in Windows opens up a whole host of potential exploits including but not limited to recording all internet traffic, all keystrokes, listing all files & programs, accessing memory of other programs and more. AAA client-side anticheats require some pretty incredible trust in the vendor to not be either evil or incompetent.

[–] uis@lemmy.world 2 points 1 year ago (1 children)

This is because on Windows it's relatively easy to run kernel-level code via drivers

Buuut there is nothing stopping a person from using virtualization.

[–] BURN@lemmy.world 3 points 1 year ago (1 children)

There’s generally other checks around virtualization. Both VMs and even dedicated KVMs result in triggering the AC generally

[–] uis@lemmy.world 2 points 1 year ago* (last edited 1 year ago)

AC somehow aren't triggered when virtualization is disabled in bios.

Alternatively binary translation or custom processors.

EDIT: there are some public info suggesting that most of detection caused by misconfiguration.

[–] Excrubulent@slrpnk.net 1 points 1 year ago

Right so on a technical level it is actually harder to do client side anti-cheat?

Thanks for the information. That hardware backed attestation reminds me of Little Brother by Cory Doctorow, where hardware DRM was introduced and then forcibly deprecated when it was found to be vulnerable... so of course the vulnerable hardware was now worthless except on the black market where it was worthwhile to pirates because it was known to be already cracked.