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devopscritical PriorityID: cilium-tetragon-kernel-enforcement-standard

Cilium Tetragon In-Kernel Runtime Enforcement and Namespace Escape Prevention

Enforces sub-microsecond in-kernel detection and synchronous termination (SIGKILL) of unauthorized namespace escapes, privilege escalations, and binary executions using Cilium Tetragon TracingPolicies. Mandates deterministic matchArgs, matchBinaries, and synchronous SIGKILL actions within the eBPF hook rather than user-space post-facto audit logging.

Prohibited Anti-Pattern: Passive User-Space Audit Logging for Kernel Exploits and Namespace Escapes

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---
description: Cilium Tetragon In-Kernel Runtime Enforcement and Namespace Escape Prevention - Enforces sub-microsecond in-kernel detection and synchronous termination (SIGKILL) of unauthorized namespace escapes, privilege escalations, and binary executions using Cilium Tetragon TracingPolicies. Mandates deterministic matchArgs, matchBinaries, and synchronous SIGKILL actions within the eBPF hook rather than user-space post-facto audit logging.
globs: deploy/tetragon/**/*.yaml, k8s/**/*.yaml, infra/security/tetragon/**/*.yaml, helm/tetragon/**/*.yaml
alwaysApply: true
verified_by: "agentrules.org"
license: "CC-BY-4.0"
source: "https://agentrules.org/rules/cilium-tetragon-kernel-enforcement-standard"
---

# Cilium Tetragon In-Kernel Runtime Enforcement and Namespace Escape Prevention

> **Severity**: CRITICAL | **Category**: devops
> **Anti-Pattern Warning**: Passive User-Space Audit Logging for Kernel Exploits and Namespace Escapes

## System Constraints
You are a Principal Security and Infrastructure Architect enforcing Cilium Tetragon eBPF kernel-level runtime enforcement. You must mandate TracingPolicies configured with in-kernel SIGKILL enforcement for suspicious namespace transitions, capability abuse, and out-of-spec binary executions, rejecting passive post-exploit audit policies.

## Strict Guidelines
- Engineers MUST ALWAYS configure `message` and `action: Sigkill` on critical TracingPolicy hooks (e.g., `sys_enter_setns`, `sys_enter_capset`, `commit_creds`) to terminate processes in-kernel before state mutation occurs.
- Engineers MUST NOT rely on passive Tetragon events without kernel enforcement for high-criticality vectors like namespace traversal (`setns`) or mount manipulation (`sys_mount`).
- TracingPolicies MUST scope selectors using `matchNamespaces` or deterministic pod labels (`matchLabels`) alongside binary path restrictions to prevent kernel policy exhaustion and blast-radius drift.
- TracingPolicies SHOULD instrument LSM hooks (e.g., `bprm_check_security`, `capable`) when available in the kernel (>= 5.7) to leverage synchronous deny capabilities over raw kprobes.
- TracingPolicies MUST explicitly define `matchArgs` operators (e.g., `Equal`, `Prefix`) and exact index bindings to eliminate evasion via argument padding or symlink aliasing.

## Bad vs Good Implementations
### Prevent Namespace Escapes (sys_enter_setns) via In-Kernel SIGKILL

#### Bad Antipattern (AI Common Hallucination)
> **Why it fails**: Passive observability allows unauthorized processes to finish entering target host/container namespaces and executing payloads before external orchestrators can respond, rendering defense useless against sub-millisecond automated exploits.
```yaml
apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: audit-setns-calls
spec:
  kprobes:
    - call: "sys_enter_setns"
      syscall: true
      args:
        - index: 0
          type: "int"
        - index: 1
          type: "int"
      # Flaw: No action specified. Defaults to user-space audit logging via gRPC export.
      # Attacker completes namespace transition before alert is ingested.
```

#### Production Standard (Correct)
> **Standard**: Injects an eBPF filter directly into the kernel's `sys_enter_setns` path. When a matching namespace flag is evaluated inside a target pod, eBPF terminates the thread via immediate SIGKILL in sub-microsecond latency, preventing the context switch.
```yaml
apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: block-unauthorized-setns
spec:
  kprobes:
    - call: "sys_enter_setns"
      syscall: true
      args:
        - index: 0
          type: "int"
        - index: 1
          type: "int"
      selectors:
        - matchNamespaces:
            - namespace: production
              operator: In
          matchArgs:
            - index: 1
              operator: "Equal"
              values:
                - "0x40000000" # CLONE_NEWUSER
                - "0x20000000" # CLONE_NEWPID
                - "0x00020000" # CLONE_NEWNET
          matchActions:
            - action: Sigkill
```
Recommended MCP Servers (mcp-serverlist.com)

Equip agent with system tools to verify code for this stack.

Kubernetes Cluster Inspector
Validates live Tetragon DaemonSet health, CRD definitions, and applied TracingPolicies across Kubernetes nodes.
Recommended Agent Skills (askills.dev)

Ready-to-use executable skill functions tailored to this stack.

Tetragon CLI Log & Policy Analyzer
Validates TracingPolicy YAML correctness, verifies BPF bytecode compilation, and prints live kernel hook events via `tetra getevents`.
Architectural Specification & Invariant Rationale

Architectural Invariant Design: Cilium Tetragon In-Kernel Runtime Enforcement and Namespace Escape Prevention

Cilium Tetragon In-Kernel Runtime Enforcement and Namespace Escape Prevention defines an industrial-grade behavioral standard for devops engineering. Enforces sub-microsecond in-kernel detection and synchronous termination (SIGKILL) of unauthorized namespace escapes, privilege escalations, and binary executions using Cilium Tetragon TracingPolicies. Mandates deterministic matchArgs, matchBinaries, and synchronous SIGKILL actions within the eBPF hook rather than user-space post-facto audit logging. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: Passive User-Space Audit Logging for Kernel Exploits and Namespace Escapes Without an explicit system instruction file, developers spend hours debugging silent failures.
Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure ModeAI Symptom (The Anti-Pattern)SeverityProduction Impact & Remedy
AI Hallucination & Deprecation DriftPassive User-Space Audit Logging for Kernel Exploits and Namespace EscapesCritical
Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production.
Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture InconsistencyAI assistants produce mixed paradigms across files, creating fragmented codebase conventions.Medium
Increases cognitive load during code reviews and leads to maintenance debt across engineering teams.
Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.
Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

1

Engineers MUST ALWAYS configure `message` and `action

Engineers MUST ALWAYS configure `message` and `action: Sigkill` on critical TracingPolicy hooks (e.g., `sys_enter_setns`, `sys_enter_capset`, `commit_creds`) to terminate processes in-kernel before state mutation occurs.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
2

Engineers MUST NOT rely on passive Tetragon events without kernel enforcement for high-criticality vectors like namespace traversal (`setns`) or mount manipulation (`sys_mount`).

Engineers MUST NOT rely on passive Tetragon events without kernel enforcement for high-criticality vectors like namespace traversal (`setns`) or mount manipulation (`sys_mount`).

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
3

TracingPolicies MUST scope selectors using `matchNamespaces` or deterministic pod labels (`matchLabels`) alongside binary path restrictions to prevent kernel policy exhaustion and blast-radius drift.

TracingPolicies MUST scope selectors using `matchNamespaces` or deterministic pod labels (`matchLabels`) alongside binary path restrictions to prevent kernel policy exhaustion and blast-radius drift.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
4

TracingPolicies SHOULD instrument LSM hooks (e.g., `bprm_check_security`, `capable`) when available in the kernel (>= 5.7) to leverage synchronous deny capabilities over raw kprobes.

TracingPolicies SHOULD instrument LSM hooks (e.g., `bprm_check_security`, `capable`) when available in the kernel (>= 5.7) to leverage synchronous deny capabilities over raw kprobes.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
5

TracingPolicies MUST explicitly define `matchArgs` operators (e.g., `Equal`, `Prefix`) and exact index bindings to eliminate evasion via argument padding or symlink aliasing.

TracingPolicies MUST explicitly define `matchArgs` operators (e.g., `Equal`, `Prefix`) and exact index bindings to eliminate evasion via argument padding or symlink aliasing.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
Technical Questions & Answers

Frequently Asked Technical Questions

Common questions developers face when configuring AI coding assistants for this stack:

Q:Why is Cilium Tetragon In-Kernel Runtime Enforcement and Namespace Escape Prevention critical for AI coding assistants?

Enforces sub-microsecond in-kernel detection and synchronous termination (SIGKILL) of unauthorized namespace escapes, privilege escalations, and binary executions using Cilium Tetragon TracingPolicies. Mandates deterministic matchArgs, matchBinaries, and synchronous SIGKILL actions within the eBPF hook rather than user-space post-facto audit logging. Without explicit behavioral boundaries, AI coding assistants (Cursor, Claude Code, Windsurf, Codex) rely on training data averages, which frequently produce deprecated, inefficient, or vulnerable code patterns.

Q:How does adopting this rule prevent AI hallucinations?

This rule explicitly declares what the AI must avoid (Passive User-Space Audit Logging for Kernel Exploits and Namespace Escapes) and prescribes verified positive examples. Grounding the LLM with negative and positive pairs eliminates guesswork.

Q:Which AI coding environments are supported?

This specification is multi-platform compatible: Cursor (.cursor/rules/*.mdc & .cursorrules), Anthropic Claude Code (CLAUDE.md), Windsurf (.windsurfrules), Codex / Cline (AGENTS.md), and GitHub Copilot (.github/copilot-instructions.md).

Q:Can I combine this rule with other technology stacks?

Yes. Use the Interactive Stack Builder or download an Agent Pack to merge this rule with other frontend, backend, database, security, and DevOps rules without syntax collision.

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Citation & Open Source Attribution Guidelines

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