[Chromebooks] fattire:
Hey y'all.

As you may have heard, there's apparently a nasty bug in hyperthreading that affects a lot of kaby lake and skylake Intel processors. I was curious if, as a week-old owner of a Chromebook Pro, I was affected. There's a perl script you can run to see if this will affect your device. Unfortunately, perl isn't built-into my chromebook, so I quickly and sloppily converted it to bash. I'm sad to report that, at least according to this script which was based on the debian post above, the bug does exist on the Chromebook Pro and, as of the current (6/25/17) canary build of Chrome, is unfixed. I guess to do so, the intel microcode needs to be updated from 0x8a to at least 0xb9. Dunno if the debian installer can be used, but I can only assume Google's on it.

There appear to be a number of chromebooks that might be (?) hit by this. If I'm not mistaken the asus c302ca has the same or similar m3 processor, for example. Dunno, but if you want to test your Intel chromebook, I think you can just go to ctrl-alt-T, get a shell, then pipe the script through bash. This way you don't have to worry about saving the file anywhere (on a read-only system). To do this, you'd do something like:

$ curl https://gist.githubusercontent.com/...e89a37585d6752de0a38f6c6a2449/intelchecker.sh | bash

Output:

Checking your CPUs....

cpu 0:

It's an Intel. Checking model & stepping...

Your CPU is affected by the issue. You should install the latest intel-microcode.

Yours is version 0x8a (138), but you should have at least 0xb9 (185).

cpu 1:

It's an Intel. Checking model & stepping...

Your CPU is affected by the issue. You should install the latest intel-microcode.

Yours is version 0x8a (138), but you should have at least 0xb9 (185).

cpu 2:

It's an Intel. Checking model & stepping...

Your CPU is affected by the issue. You should install the latest intel-microcode.

Yours is version 0x8a (138), but you should have at least 0xb9 (185).

cpu 3:

It's an Intel. Checking model & stepping...

Your CPU is affected by the issue. You should install the latest intel-microcode.

Yours is version 0x8a (138), but you should have at least 0xb9 (185).

HOWEVER, A WARNING: it's

never EVER

a good habit to just download stuff off the internet and run right away. So read the code first and make sure it's kosher before you run it. There may be (let's face it, probably are) bugs. For one thing, I noticed that it gives slightly different output sometimes when it runs, probably due to reading and sedding /proc/cpuinfo on the fly.

This isn't a project I want to spend a lot of time on, so run it a few times to verify the output , or for pete's sake just look at /proc/cpuinfo to determine if you're affected and follow debian's advice here. As I said i converted this to bash because I knew it was going to be natively on all Chromebooks whereas at least typing "perl", perl couldn't be found. I should have converted this to python--I don't know what I was thinking. Bash is terrible (I just learned) w/regular expressions. Anyway, I tested it on a raspberry pi, an old PC, a mac, and an affected chromebook and I think it worked. It's GPLd, and you are advised to run at your own risk.

You can read more on hacker news. If anyone notices any bugs I'll update the script and this post. Cheers.

Update: Reported to Google. If this affects your device, consider starring it so that Google notices it and hopefully fixes it.