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securitycritical PriorityID: tetragon-ebpf-namespace-isolation-standard

Tetragon In-Kernel Synchronous Syscall Namespace Isolation Enforcement

Mandates synchronous in-kernel process termination (Sigkill) via Cilium Tetragon TracingPolicy for unauthorized container namespace transitions involving setns and pivot_root syscalls. Guarantees container breakout attempts are blocked directly inside the Linux eBPF execution layer before privilege boundaries are crossed, replacing latency-prone user-space audit daemons.

Prohibited Anti-Pattern: Passive Audit Logging of Container Namespace Escapes and Post-Mortem Alerts

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---
description: Tetragon In-Kernel Synchronous Syscall Namespace Isolation Enforcement - Mandates synchronous in-kernel process termination (Sigkill) via Cilium Tetragon TracingPolicy for unauthorized container namespace transitions involving setns and pivot_root syscalls. Guarantees container breakout attempts are blocked directly inside the Linux eBPF execution layer before privilege boundaries are crossed, replacing latency-prone user-space audit daemons.
globs: **/*.yaml, **/*.yml, deploy/**/*.yaml, k8s/**/*.yaml, infra/**/*.yaml
alwaysApply: true
verified_by: "agentrules.org"
license: "CC-BY-4.0"
source: "https://agentrules.org/rules/tetragon-ebpf-namespace-isolation-standard"
---

# Tetragon In-Kernel Synchronous Syscall Namespace Isolation Enforcement

> **Severity**: CRITICAL | **Category**: security
> **Anti-Pattern Warning**: Passive Audit Logging of Container Namespace Escapes and Post-Mortem Alerts

## System Constraints
You are a Principal Security Architect enforcing Cilium Tetragon eBPF namespace isolation standards. Enforce deterministic in-kernel prevention (Sigkill) on unauthorized namespace manipulation syscalls (setns, pivot_root, unshare) across all container execution environments.

## Strict Guidelines
- Engineers MUST ALWAYS enforce synchronous `Sigkill` actions on unauthorized `sys_enter_setns` and `sys_enter_pivot_root` hook points within Tetragon TracingPolicies.
- Engineers MUST NOT rely on asynchronous user-space audit events (e.g., `Post` actions without kernel kill hooks) to mitigate zero-day container breakout vectors.
- Policies MUST scope syscall hooks to non-host namespaces using `matchNamespaces` or selectors to avoid killing legitimate host daemon operations.
- TracingPolicies SHOULD whitelist authorized container runtime binaries (such as `runc` or `containerd-shim`) strictly by verified binary hashes or immutable system paths under `/usr/bin/`.
- Workloads MUST NEVER be granted `CAP_SYS_ADMIN` or `CAP_SYS_CHROOT` capabilities without an active in-kernel Tetragon TracingPolicy enforcing strict namespace boundary invariants.

## Bad vs Good Implementations
### Tetragon In-Kernel Breakout Prevention vs Passive Audit

#### Bad Antipattern (AI Common Hallucination)
> **Why it fails**: The policy merely logs syscall execution via 'action: Post' to user space. A container breakout payload can execute subsequent exploits (e.g., executing a host binary or reading host credentials) before an external monitoring tool can process the alert and issue a mitigation command.
```yaml
apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: audit-namespace-breakouts
spec:
  kprobes:
    - call: "sys_setns"
      syscall: true
      args:
        - index: 0
          type: "int"
        - index: 1
          type: "int"
      selectors:
        - matchActions:
            - action: Post # FAILS: Only logs the event to Tetragon agent; breakout succeeds
    - call: "sys_pivot_root"
      syscall: true
      selectors:
        - matchActions:
            - action: Post # FAILS: Passive observation cannot prevent root filesystem manipulation
```

#### Production Standard (Correct)
> **Standard**: The updated TracingPolicy uses 'action: Sigkill' directly inside eBPF probes triggered on 'sys_enter_setns' and 'sys_enter_pivot_root' for non-host namespaces. The Linux kernel kills the calling process synchronously before the namespace transition occurs, thwarting zero-day breakout attempts.
```yaml
apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: block-namespace-breakouts
spec:
  kprobes:
    - call: "sys_setns"
      syscall: true
      args:
        - index: 0
          type: "int"
        - index: 1
          type: "int"
      selectors:
        - matchNamespaces:
            - namespace: Pid
              operator: NotIn
              values: ["host"]
          matchActions:
            - action: Sigkill # ENFORCES: Terminates thread synchronously inside eBPF
    - call: "sys_pivot_root"
      syscall: true
      selectors:
        - matchNamespaces:
            - namespace: Mount
              operator: NotIn
              values: ["host"]
          matchActions:
            - action: Sigkill # ENFORCES: Kernel aborts pivot_root immediately
```
Recommended MCP Servers (mcp-serverlist.com)

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

Kubernetes Resource Gateway
Inspects and validates Tetragon TracingPolicy and TracingPolicyNamespaced CRDs directly against active Kubernetes clusters.
Recommended Agent Skills (askills.dev)

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

Tetragon CLI Enforcement Validator
Validates Tetragon JSON export logs, inspects active eBPF sensor programs, and tests in-kernel Sigkill triggers.
Architectural Specification & Invariant Rationale

Architectural Invariant Design: Tetragon In-Kernel Synchronous Syscall Namespace Isolation Enforcement

Tetragon In-Kernel Synchronous Syscall Namespace Isolation Enforcement defines an industrial-grade behavioral standard for security engineering. Mandates synchronous in-kernel process termination (Sigkill) via Cilium Tetragon TracingPolicy for unauthorized container namespace transitions involving setns and pivot_root syscalls. Guarantees container breakout attempts are blocked directly inside the Linux eBPF execution layer before privilege boundaries are crossed, replacing latency-prone user-space audit daemons. 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 Audit Logging of Container Namespace Escapes and Post-Mortem Alerts 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 Audit Logging of Container Namespace Escapes and Post-Mortem AlertsCritical
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 enforce synchronous `Sigkill` actions on unauthorized `sys_enter_setns` and `sys_enter_pivot_root` hook points within Tetragon TracingPolicies.

Engineers MUST ALWAYS enforce synchronous `Sigkill` actions on unauthorized `sys_enter_setns` and `sys_enter_pivot_root` hook points within Tetragon TracingPolicies.

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 asynchronous user-space audit events (e.g., `Post` actions without kernel kill hooks) to mitigate zero-day container breakout vectors.

Engineers MUST NOT rely on asynchronous user-space audit events (e.g., `Post` actions without kernel kill hooks) to mitigate zero-day container breakout vectors.

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

Policies MUST scope syscall hooks to non-host namespaces using `matchNamespaces` or selectors to avoid killing legitimate host daemon operations.

Policies MUST scope syscall hooks to non-host namespaces using `matchNamespaces` or selectors to avoid killing legitimate host daemon operations.

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 whitelist authorized container runtime binaries (such as `runc` or `containerd-shim`) strictly by verified binary hashes or immutable system paths under `/usr/bin/`.

TracingPolicies SHOULD whitelist authorized container runtime binaries (such as `runc` or `containerd-shim`) strictly by verified binary hashes or immutable system paths under `/usr/bin/`.

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

Workloads MUST NEVER be granted `CAP_SYS_ADMIN` or `CAP_SYS_CHROOT` capabilities without an active in-kernel Tetragon TracingPolicy enforcing strict namespace boundary invariants.

Workloads MUST NEVER be granted `CAP_SYS_ADMIN` or `CAP_SYS_CHROOT` capabilities without an active in-kernel Tetragon TracingPolicy enforcing strict namespace boundary invariants.

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 Tetragon In-Kernel Synchronous Syscall Namespace Isolation Enforcement critical for AI coding assistants?

Mandates synchronous in-kernel process termination (Sigkill) via Cilium Tetragon TracingPolicy for unauthorized container namespace transitions involving setns and pivot_root syscalls. Guarantees container breakout attempts are blocked directly inside the Linux eBPF execution layer before privilege boundaries are crossed, replacing latency-prone user-space audit daemons. 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 Audit Logging of Container Namespace Escapes and Post-Mortem Alerts) 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.

Open Specification · CC BY 4.0·Free for Personal, Team & Commercial In-Repo Use

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This specification is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). You are completely free to adapt and share this rule in your workspace. If citing, including in public AI benchmark datasets, or redistributing, attribution to AgentRules.org is required.

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