As someone who develops microVMs it doesn't really matter to me that they were asked to find a way, I really care that they found any way at all. MicroVMs aim to protect against malicious workloads and that clearly didn't work here.

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rao-v 3 hours ago | parent | next [-]

Ask the least smart LLM you have access to (I tried gemini lite flash) to make a list of ways for processes in microVMs to use a sidechannel attack to talk to each other and you'll get quite a list (including obviously cache hits/misses). Heck a smart CS junior would come up with it. It's well studied!

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saidnooneever 2 hours ago | parent [-]

this is just for common designs..you can design much better than common designs if you free your mind from old OS dev thinking if you read all the manuals yourself.

AI wont help u there :-). they will tell u how to build what others already did, which obviously is not good enough

	▲	kylofon an hour ago \| parent [-]
		I don't think that's the full picture. If you include these manuals as reference for a strong model, it will reason pretty well based off of that, I recon.

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rcxdude an hour ago | parent | prev | next [-]

The microVMs probably don't have "two co-operating workloads are able to communicate" in their threat model. The main concern would be if a malicious payload was able to affect or extract data from any other VM.

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alanfranz 17 minutes ago | parent | prev | next [-]

I’m not sure I see a real threat here.

If you’re running an untrusted workload, you’re already running it.

Whether it can communicate with another untrusted workload, even though it should be separated, meh.

Unexpected? Probably. but I’m not sure it’s a security risk.

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Melatonic 2 hours ago | parent | prev | next [-]

Makes sense when you think about it- CPU cache would be a layer / vulnerability level up from the microVM layer

Also a somewhat common exploit pattern for low level stuff (along with dram and cpu cache is not all that different)

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saidnooneever 2 hours ago | parent | prev [-]

properly implementing things like iommu, amd-vi, svm/hvms and such things more granularly can easily avoid this kind of crap. it costs a lot of processing and performance which is why people skip over it or dont do it.. or maybe they dont read CPU manuals anymore. idk..

its relatively easy to reset caches etc. between contexts. so them it becomes the game of what a context is.