---
title: "HOST-KRN-030 BPF JIT Hardening Off"
canonical: https://openvapt.com/checks/HOST-KRN-030.html
html: https://openvapt.com/checks/HOST-KRN-030.html
site: OpenVAPT, https://openvapt.com/
license: OpenVAPT Source-Available Licence 1.3, https://openvapt.com/legal/licence-text.html
modified: 2026-10-14
version: 0.1.0-alpha.6
---

# HOST-KRN-030 BPF JIT Hardening Off

Checks that the BPF just-in-time compiler blinds constants in generated code for every user.

- Domain: Server
- Severity: Low
- Control category: Secure Configuration
- Fix effort: low
- CVSS v3.1 vector: `CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N`
- CIS Controls v8: 4.1
- NIST CSF 2.0: PR.PS-01
- CWE: CWE-1188
- NIST SP 800-53 Rev. 5: SC-7, CM-6
- Benchmark topic: Kernel parameters: net.core.bpf_jit_harden (topic only, no benchmark text)

## Why It Matters

Without hardening, attacker-chosen constants in BPF programs land in executable kernel memory, a known technique for building kernel exploit payloads.

## How It Detects

Reads /proc/sys/net/core/bpf_jit_harden directly (no command is run) and compares it with the hardened value 2.

## How to Fix

Create /etc/sysctl.d/60-openvapt-hardening.conf containing:  net.core.bpf_jit_harden = 2  then apply with: sysctl --system

## How to Verify

```
sysctl net.core.bpf_jit_harden  should print 2.
```

## Learn the Theory

- [P1 Linux Server Hardening](https://openvapt.com/academy/p1.md)
- [P17 Kernel, Filesystem and Boot Hardening](https://openvapt.com/academy/p17.md)

## References

- [Kernel Self Protection Project, Recommended Settings](https://kspp.github.io/Recommended_Settings)

## Source Code

https://github.com/OpenVAPT/openvapt/blob/574f7f3333c44b75a3c649e2d93a76d507f75adf/internal/checks/host/kernel.go

Run it: `openvapt scan --only HOST-KRN-030`. Read it offline: `openvapt explain HOST-KRN-030`.

---

OpenVAPT is academic, non-commercial, source-available and built by AI Cybersecurity Engineers (AI systems, not people). Free for your own use on machines you own or control, 100% at your own risk; not for sale and not for providing services. This page in HTML: https://openvapt.com/checks/HOST-KRN-030.html. Part of OpenVAPT Check Catalogue. How to cite: https://openvapt.com/cite.html. Site summary for models: https://openvapt.com/llms.txt.