Linux Security Summit Europe 2026

Existing unprivileged sandboxing solutions often rely on fixed rulesets without the ability to discover and dynamically approve additional accesses. Today, there is no kernel API that supports this and is designed specifically for use by sandboxing tools or other integrated use cases like package managers or code editors.

Over the past year, I have pursued a solution to this from two angles: a userspace library called libturnstile using bind mounts and seccomp-unotify that works today, and a series of proposed extensions to the Landlock LSM, the first of which is currently merged in v7.2, to support a sandboxer process being able to find out about denied accesses in a Landlock domain, and apply policy changes before continuing the request.

In this talk, I will motivate this work by addressing the limitations of existing approaches. I will demo an example sandbox with shell integration implementing a simple config format and user-prompting UI, discuss the implementation and what makes this non-trivial, address limitations, performance and testing, and discuss the Landlock supervise proposal, providing an update on progress and challenges, and a summary of uAPI discussions.