alt Hacker News350,000 of mostly Rust SLOC [1] ... And the upstream sandboxes aren't even vendored!
I'd be way more confident building upon something I can grasp and understand. [2]
[1]: https://ghloc.dev/microsoft/mxc [2]: https://github.com/sandbox-utils/sandbox-run
Replies
its-summertime • today at 11:11 AM
I feel a better metric is `lines changed / time` as that affects what will be audited as time goes on
That being said, a month of MXC has more line changes than 2-3 years of runc
If you look around the files, I think at least half is comments or unit tests, e.g.
https://ghloc.dev/microsoft/mxc?branch=main&locsPath=%5B%22s...
That site thinks this file has 2.9k sloc and doesn't seem to parse rust comments. In reality, there's only 1,465 sloc; and 635 loc of tests.
Definitely nowhere near 350k sloc.
--
As for your sandbox run: it's a single-contributor project, seems to have only have basic smoke tests, and has a few major/critical security issues:
* _generate_seccomp_filter compares newline-deliminated syscalls, against a multi-line blocklist, meaning the entire function doesn't block anything and is essentially a no-op.
* Main script invokes working directory's .env as shellcode, before switching into restricted filesystems and dropping capabilities. Attacker-controlled .env can run shellcode with full privileges.
* Lots of race conditions which I haven't verified, but doesn't really matter.
I'd make PRs, but I don't think it's a good idea to try and DIY a sandboxing system in bash with minimal SLOC as the target in the first place. I'm also slightly concerned that most of your comments on HN seem to be promoting this repo?