Intel Finds Bug in AMD's Spectre Mitigation – AMD Issues Fix | Hacker News Reader

Intel Finds Bug in AMD's Spectre Mitigation – AMD Issues Fix

tomshardware.com

121 pointsNews-Dog20 comments

The page now [EDIT: as of writing] points to a 404, and has been excluded from the Wayback Machine. However, it's still in Google Cache, which I've saved to https://web.archive.org/web/20220312144415/https://webcache..... The article might've been retracted for a reason though, IDK.

OP: I've deleted my browser-cache and checked at UTC 15:00 2022-03-12 ;

<https://www.tomshardware.com/news/intel-amd-spectre-v2-vulne...>

Opens fine for me here?

It seems back up?

same here, loading fine on fresh load (opened it on my mobile earlier)

This kind of thing shows that Intel gives its STORM security team a lot of autonomy. The optics of this couldn’t be better, honestly.

If they found a problem and didn't report it, and someone leaked that fact to the press, that would be some very bad optics indeed, autonomy or no.

So I've been hobbling my CPUs performance for the past 4 years with a mitigation that doesn't actually mitigate.

Must be a day ending in y.

Oh, but it does mitigate - just turns out it don't mitigate enough.

s/reservation/mitigation/ https://youtu.be/A-brgkkjnHc

Jokes aside - I understand the difficulty to adequately defend against meltdown/spectre. When the exploits were released I was running a service which definitely needed protection from this type of attack. Ironically we had just finished a set of optimizations that would have reduced our cpu costs quite nicely, the mitigations ate all those wins and more.

I guess I'm still bitter - I no longer own that system but it really frustrated me to hear that it apparently was still vulnerable to spectre style attacks.

> ate all those wins and more.

At least you still have a relative advantage: if you had not optimized, the CPU costs would have increased even more.

I turned them all off on all my production servers

they don't run arbitrary untrusted code and send a LOT of packets, those mitigations really hurt

I think that's the smart thing to do. Default to safe, let people evaluate their threat model and disable as needed.

I'm curious, what options did you disable?

Add 'mitigations=off' to the kernel command line (assuming you're using linux)

We did it for most of our GCP images

Right, I'm not sure Spectre is worth worrying about outside of big multi-user systems, or a web browser executing Javascript. Otherwise if you're executing untrusted code, you're in big trouble regardless.

That works on bare metal you control. If you rent something with VM / hypervisor the mitigations are important to protect from other VMs on the machine.

Mitigation between VMs is only effective when done from the hypervisor. Mitigations within a VM can only counter intra VM data leaks.

Also recently: https://news.ycombinator.com/item?id=30603600

Aww.

Ironic.

In the article they explain it. People nudged intel to mitigate spectre like AMD. They looked into how they did it to learn more and found some flaws and responsibly disclosed them.

Reply on news.ycombinator.com