Re: [RESEND PATCH v6 0/5] proc: subset=pid: Relax check of mount visibility

Dan Klishch
2025-12-13T05:06:48Z

Hello Alexey,

Would it be possible to revive this patch series?

I wanted to add an additional downstream use case that would benefit
from this work. In particular, I am trying to run the sandbox
sunwalker-box [1] without root privileges and/or inside a container.

The sandbox aims to prevent cross-run communication via side channels,
and PID allocation is one such channel. Therefore, it creates a new PID
namespace and mounts the corresponding procfs instance inside of the
sandbox. This currently works without a real root when procfs is fully
accessible, but obviously fails otherwise.

Thanks,
Dan Klishch

[1] https://github.com/purplesyringa/sunwalker-box/