LinuxArena: A Control Setting for AI Agents in Live Production Software Environments

TL;DR

LinuxArena is a comprehensive control setting for testing AI agents in live software environments, enabling research on attack and defense strategies with diverse tasks and real-world relevance.

Contribution

The paper introduces LinuxArena, the largest and most diverse control setting for software engineering, and demonstrates its utility through sabotage and monitor evaluation experiments.

Findings

Claude Opus 4.6 detects approximately 77% of sabotage attempts.

LaStraj dataset reveals current attack policies do not fully exploit LinuxArena.

LinuxArena offers significant headroom for advancing control protocols.

Abstract

We introduce LinuxArena, a control setting in which agents operate directly on live, multi-service production environments. LinuxArena contains 20 environments, 1,671 main tasks representing legitimate software engineering work, and 184 side tasks representing safety failures such as data exfiltration and backdooring, making it the largest and most diverse control setting for software engineering to date. We validate LinuxArena is useful for control research by running sabotage evaluations, which measure whether attackers can complete side tasks while working on main tasks, and monitor evaluations, which measure a monitor model's ability to detect sabotage attempts. Against a GPT-5-nano trusted monitor at a 1\% step-wise false positive rate, Claude Opus 4.6 achieves roughly a 23% undetected sabotage success rate. We additionally release LaStraj, a dataset of human-crafted attack trajectories that evade monitors at substantially higher rates than any model-generated attacks we elicited, showing that current attack policies do not saturate LinuxArena. These results suggest that LinuxArena has meaningful headroom for both attackers and defenders, making it a strong testbed for developing and evaluating future control protocols.