As far as I know, Firecracker, gVisor, and Kata Containers are the solution here. They use VM primitives (x64_64 and ARM64 extensions) and have lighter codebases
But I don't have any direct experience with any of them. I'd be curious what people who have built on top of them think
edit: OK it looks like Kata can use Firecracker, so as far as isolation, it's either Firecracker or gVisor. And Firecracker is the VMM I mentioned, but gVisor is quite different -- it's more like a user space kernel that emulates syscalls.
As I understand it Kata supports multiple VMM backends, Firecracker, QEmu, Cloud Hypervisor, and their own Dragonball. Except QEmu, I believe those are all built on crates in the rust-vmm ecosystem, each making slightly different tradeoffs.
Podman supports using KVM backed virtualization for containers via libkrun: `podman run --runtime=krun` . Still not the end-all-be-all security boundary, but better I think.
Depends on the threat model. Security is not black-and-white.
Containers protect against "I don't trust this curlpipe to not crap all over my dotfiles," rather than, "there might be a sandbox escape attack in this random file I downloaded."
If a VM is not sufficient for your threat model, I'm curious what is?
I think until something hardware-based like CHERI becomes widely deployed (which seems extremely unlikely in the near to mid term given), we're going to keep seeing VM escape CVEs pop up indefinitely.
I definitely wouldn't trust standard Linux style containers that expose a shared Linux kernel at the moment, there's been far too many LPE and container breakout vulnerabilities this year. It's possible that in future if the kernel gets a lot more hardened, that could change but things like Firecracker are a better bet from a security standpoint.
https://github.com/nolabs-ai/nono
https://news.ycombinator.com/item?id=30623372 (250 points | March 10, 2022 | 27 comments)
https://news.ycombinator.com/item?id=22232705 (267 points | Feb 4, 2020 | 29 comments)
https://news.ycombinator.com/item?id=15608435 (440 points | Nov 2, 2017 | 53 comments)
I don't think we should consider containers to be a security boundary. Even full VMs can be escaped, and have been, many times.
The fact that this is possible in the first place makes me think we need a much better approach.
https://firecracker-microvm.github.io/
https://gvisor.dev/
https://katacontainers.io/
But I don't have any direct experience with any of them. I'd be curious what people who have built on top of them think
edit: OK it looks like Kata can use Firecracker, so as far as isolation, it's either Firecracker or gVisor. And Firecracker is the VMM I mentioned, but gVisor is quite different -- it's more like a user space kernel that emulates syscalls.
https://github.com/smol-machines/smolvm
Containers protect against "I don't trust this curlpipe to not crap all over my dotfiles," rather than, "there might be a sandbox escape attack in this random file I downloaded."
If a VM is not sufficient for your threat model, I'm curious what is?