---
id: "CVE-2026-99160"
kind: "vulnerability"
aliases: ["CVE-2026-99160"]
title: "Linux kernel: reading ring-buffer metadata for offline CPU crashes"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "linux"]
not_affected_if: []
published_at: "2026-10-28T11:17:36+00:00"
first_seen_at: "2026-10-28T11:32:36+00:00"
updated_at: "2026-10-28T11:35:45+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99160", "first_seen_at": "2026-10-28T11:32:36+00:00"}]
---

# Linux kernel: reading ring-buffer metadata for offline CPU crashes

The Linux kernel's ring buffer tracing interface creates a buffer_meta file for every possible CPU, including CPUs that never came online. Reading one of those files dereferences a NULL buffer pointer, which crashes the kernel.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-10-28T11:32:36+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99160

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

ring-buffer: Do not show buffer_meta for CPUs without a buffer

The per_cpu/cpuN/buffer_meta files are created for every possible CPU,
but buffer->buffers[cpu] is only allocated once that CPU comes online.
Reading the file of a CPU that never came online dereferences a NULL
cpu_buffer in rbm_start().

Fail the open with -ENODEV when the CPU has no buffer, as the other
per CPU ring buffer interfaces do.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_