KRAKENGUARD: Towards Fine-Grained eBPF Isolation#

Jainil Patel (IIT Roorkee), Lucas Graeff Buhl-Nielsen (Quantco), Adrien Ghosn (Microsoft), Marios Kogias (Imperial College London)

• Why: eBPF's security model is the dirty secret of the ecosystem — CAP_BPF is all-or-nothing, which is untenable as multi-tenant eBPF/XDP programs from different parties land on the same host. This is a serious attack on exactly that gap.
• What: A trusted user-space manager enforcing fine-grained, policy-driven constraints on eBPF bytecode at load time: restricting helper usage, memory/map access, and return values. It demonstrably blocks misuse in real-world programs, detects existing CVEs, and enables an XDP-as-a-Service use case where tenants' XDP programs run directly on the host interface without mutual interference.
• How: Symbolic execution of program paths at load time to check compliance with policy; cross-program interference detection to make co-location on the same hook safe.
• Where applicable: General Linux/eBPF environments — any platform running third-party or tenant-supplied eBPF. Load-time analysis (not runtime) so the cost is per-load; the trusted-manager design makes assumptions about who controls the host. Highly relevant to Cilium-style deployments where programs multiply across hooks.