From 732 bytes to nowhere: shutting down Copy Fail in production

What this post added

This post details Together AI's rapid response to the Copy Fail (CVE‑2026‑31431) Linux kernel vulnerability. The immediate mitigation involved disabling the `algif_aead` kernel module across the entire fleet to prevent exploitation, a process that did not require reboots and had minimal operational impact on AI workloads. The strategy for rolling out vendor patches involves staged deployment in non-production environments, followed by gradual rollout to production clusters, with rigorous testing for performance and stability. The post also highlights the addition of Copy Fail-aware signals to telemetry for enhanced detection and emphasizes a kernel exposure model that defaults to 'off' for niche interfaces, coupled with fast fleet-wide toggles and a validation pipeline for AI workloads.