---
id: "CVE-2026-99267"
kind: "vulnerability"
aliases: ["CVE-2026-99267"]
title: "Linux kernel: io_uring NAPI entries never expire, keep being polled"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["io_uring", "linux-kernel", "runtime", "self-hosted"]
not_affected_if: ["no-io-uring-napi"]
published_at: "2026-11-03T12:17:33+00:00"
first_seen_at: "2026-11-03T12:20:40+00:00"
updated_at: "2026-11-03T12:22:38+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99267", "first_seen_at": "2026-11-03T12:20:40+00:00"}]
---

# Linux kernel: io_uring NAPI entries never expire, keep being polled

The Linux kernel's io_uring busy-poll tracking computes its 60-second timeout with the wrong unit, so stale NAPI IDs are never dropped. Every network ID a ring has ever used keeps being polled on each wait, which wastes CPU and can degrade the system.

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

## Timeline

- 2026-11-03T12:20:40+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99267

## From the sources

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

io_uring/napi: make stale entries time out after 60s

With dynamic tracking a NAPI id that hasn't been seen for a minute is
meant to be dropped from the list the ring busy polls. The timeout is
added to jiffies, but it is defined as 60 * SEC_CONVERSION, and
SEC_CONVERSION isn't the number of jiffies in a second. It is the
internal factor of __timespec64_to_jiffies(), HZ scaled up by
SEC_JIFFIE_SC bits. For HZ=1000 that is 1000 << 22, which puts the
timeout at about eight years. On 32-bit the multiplication overflows.

So entries are never removed, and every id that a socket of the ring
ever had keeps being polled on each wait.

---

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