---
id: CVE-2025-40305
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN

  p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq)
  if list_empty(&m->req_list).

  However, …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN

  p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq)
  if list_empty(&m->req_list).

  However, …
severity: none
published: '2025-12-08'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T22:10:00.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40305'
references:
  - url: 'https://git.kernel.org/stable/c/242531004d7de8c159f9bfadebe33fe8060b1046'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e8fe3f07a357c39d429e02ca34f740692d88967a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00172
epssPercentile: 0.06147
ingestedAt: '2026-10-14T23:00:02.019Z'
---

## Overview

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

9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN

p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq)
if list_empty(&m->req_list).

However, if the pipe is full, we need to read more data and this used to
work prior to commit aaec5a95d59615 ("pipe_read: don't wake up the writer
if the pipe is still full").

p9_read_work() does p9_fd_read() -> ... -> anon_pipe_read() which (before
the commit above) triggered the unnecessary wakeup. This wakeup calls
p9_pollwake() which kicks p9_poll_workfn() -> p9_poll_mux(), p9_poll_mux()
will notice EPOLLIN and schedule_work(&m->rq).

This no longer happens after the optimization above, change p9_fd_request()
to use p9_poll_mux() instead of only checking for EPOLLOUT.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.