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securitycritical PriorityID: tetragon-ebpf-namespace-boundary-invariant

Tetragon eBPF Real-Time Process and Namespace Boundary Enforcement

Enforces synchronous eBPF kernel-level detection and SIGKILL termination for container namespace escape attempts and unauthorized Linux capability escalations. Restricts execution to deterministic process hierarchies and forbids runtime modification of security-sensitive syscall signatures at the kernel boundary.

Prohibited Anti-Pattern: Relying on Asynchronous User-Space Auditing or Permissive Syscall Filters for Namespace and Capability Security

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---
description: Tetragon eBPF Real-Time Process and Namespace Boundary Enforcement - Enforces synchronous eBPF kernel-level detection and SIGKILL termination for container namespace escape attempts and unauthorized Linux capability escalations. Restricts execution to deterministic process hierarchies and forbids runtime modification of security-sensitive syscall signatures at the kernel boundary.
globs: deploy/tetragon/**/*.yaml, k8s/**/*.yaml, security/policies/**/*.yaml, infra/k8s/policies/**/*.yaml
alwaysApply: true
verified_by: "agentrules.org"
license: "CC-BY-4.0"
source: "https://agentrules.org/rules/tetragon-ebpf-namespace-boundary-invariant"
---

# Tetragon eBPF Real-Time Process and Namespace Boundary Enforcement

> **Severity**: CRITICAL | **Category**: security
> **Anti-Pattern Warning**: Relying on Asynchronous User-Space Auditing or Permissive Syscall Filters for Namespace and Capability Security

## System Constraints
You are a Principal Security Architect enforcing Tetragon eBPF real-time process and namespace boundary invariants. Enforce zero-overhead in-kernel synchronous enforcement (Sigkill action) via TracingPolicies for dangerous syscalls including setns, unshare, capset, and execve. Prevent privilege escalation and asynchronous userspace detection latency windows.

## Strict Guidelines
- TracingPolicies MUST ALWAYS specify 'Sigkill' actions rather than passive 'Post' logging when intercepting namespace-hopping syscalls (sys_enter_setns, sys_enter_unshare).
- Engineers MUST NOT allow containers to acquire CAP_SYS_ADMIN, CAP_SYS_PTRACE, or CAP_SYS_CHROOT without explicit, isolated, cryptographically verified TracingPolicy waivers.
- TracingPolicies MUST match against specific binary path prefixes (e.g., /usr/bin, /app) and enforce binary execution invariants using 'matchBinaries' and 'matchNamespaces'.
- Services MUST enforce syscall parameter filtering in eBPF kernel space using 'matchArgs' filters to detect argument tampering before execution.
- Containers NEVER mount the host procfs (/proc), sysfs (/sys), or docker/containerd runtime sockets without triggering automated Tetragon synchronous termination.

## Bad vs Good Implementations
### Tetragon TracingPolicy: Namespace Escape Prevention

#### Bad Antipattern (AI Common Hallucination)
> **Why it fails**: Passive auditing or post-event logging introduces a TOCTOU (Time of Check to Time of Use) window where an attacker can escape the container namespace and compromise the host before user-space detection triggers.
```yaml
apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: audit-namespace-escape
spec:
  kprobes:
    - call: "sys_setns"
      syscall: true
      args:
        - index: 0
          type: "int"
        - index: 1
          type: "int"
      # Flaw: Passive logging only; allows race condition execution
      # before userspace SIEM can react to the escape.
```

#### Production Standard (Correct)
> **Standard**: Executes an immediate in-kernel synchronous SIGKILL via eBPF when any process inside a non-host PID namespace attempts to execute the setns syscall, preventing escape instantly with zero userspace overhead.
```yaml
apiVersion: cilium.io/v1alpha1
kind: TracingPolicy
metadata:
  name: block-namespace-escape
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
```
Recommended MCP Servers (mcp-serverlist.com)

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

Kubernetes Cluster Inspector MCP
Enables inspection and dry-run validation of Tetragon TracingPolicy custom resources against live Kubernetes clusters.
Recommended Agent Skills (askills.dev)

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

Tetragon CLI Expert
Command-line utility for managing Tetragon TracingPolicies and streaming real-time kernel telemetry.
Architectural Specification & Invariant Rationale

Architectural Invariant Design: Tetragon eBPF Real-Time Process and Namespace Boundary Enforcement

Tetragon eBPF Real-Time Process and Namespace Boundary Enforcement defines an industrial-grade behavioral standard for security engineering. Enforces synchronous eBPF kernel-level detection and SIGKILL termination for container namespace escape attempts and unauthorized Linux capability escalations. Restricts execution to deterministic process hierarchies and forbids runtime modification of security-sensitive syscall signatures at the kernel boundary. 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: Relying on Asynchronous User-Space Auditing or Permissive Syscall Filters for Namespace and Capability Security 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 DriftRelying on Asynchronous User-Space Auditing or Permissive Syscall Filters for Namespace and Capability SecurityCritical
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

TracingPolicies MUST ALWAYS specify 'Sigkill' actions rather than passive 'Post' logging when intercepting namespace-hopping syscalls (sys_enter_setns, sys_enter_unshare).

TracingPolicies MUST ALWAYS specify 'Sigkill' actions rather than passive 'Post' logging when intercepting namespace-hopping syscalls (sys_enter_setns, sys_enter_unshare).

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 allow containers to acquire CAP_SYS_ADMIN, CAP_SYS_PTRACE, or CAP_SYS_CHROOT without explicit, isolated, cryptographically verified TracingPolicy waivers.

Engineers MUST NOT allow containers to acquire CAP_SYS_ADMIN, CAP_SYS_PTRACE, or CAP_SYS_CHROOT without explicit, isolated, cryptographically verified TracingPolicy waivers.

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 match against specific binary path prefixes (e.g., /usr/bin, /app) and enforce binary execution invariants using 'matchBinaries' and 'matchNamespaces'.

TracingPolicies MUST match against specific binary path prefixes (e.g., /usr/bin, /app) and enforce binary execution invariants using 'matchBinaries' and 'matchNamespaces'.

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

Services MUST enforce syscall parameter filtering in eBPF kernel space using 'matchArgs' filters to detect argument tampering before execution.

Services MUST enforce syscall parameter filtering in eBPF kernel space using 'matchArgs' filters to detect argument tampering before execution.

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

Containers NEVER mount the host procfs (/proc), sysfs (/sys), or docker/containerd runtime sockets without triggering automated Tetragon synchronous termination.

Containers NEVER mount the host procfs (/proc), sysfs (/sys), or docker/containerd runtime sockets without triggering automated Tetragon synchronous termination.

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 eBPF Real-Time Process and Namespace Boundary Enforcement critical for AI coding assistants?

Enforces synchronous eBPF kernel-level detection and SIGKILL termination for container namespace escape attempts and unauthorized Linux capability escalations. Restricts execution to deterministic process hierarchies and forbids runtime modification of security-sensitive syscall signatures at the kernel boundary. 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 (Relying on Asynchronous User-Space Auditing or Permissive Syscall Filters for Namespace and Capability Security) 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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