---
id: CVE-2026-89709
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  lockd, nfsd: RCU-protect nlmsvc_ops dispatch

  nlmsvc_ops is published by nfsd_lockd_init() and cleared by
  nfsd_lockd_shutdown() with plain stores, while lockd dereferen…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  lockd, nfsd: RCU-protect nlmsvc_ops dispatch

  nlmsvc_ops is published by nfsd_lockd_init() and cleared by
  nfsd_lockd_shutdown() with plain stores, while lockd dereferen…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-476
  - CWE-416
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    836ce2b99bcce6d68c58edd04efbc5cd1fd581af
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    3c461a1820088fb5889d73a6522369bde45527a9
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    641e5e20852359b8c31149be4598884e30652f60
  - Linux 2.6.12
published: '2026-09-11'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T11:17:55.150'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89709'
references:
  - url: 'https://git.kernel.org/stable/c/3c461a1820088fb5889d73a6522369bde45527a9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/641e5e20852359b8c31149be4598884e30652f60'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/836ce2b99bcce6d68c58edd04efbc5cd1fd581af'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89709.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89709'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532208'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89709'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89709'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89709.mbox
  - url: 'https://kernelcve.org/list/?q=CVE-2026-89709'
  - url: 'https://git.kernel.org/stable/c/43943532c105ea8fe26039a1347cfda4ac0fcadc'
  - url: 'https://git.kernel.org/stable/c/6e7495972039f212e336e552b58cac9dd54611c3'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00552
epssPercentile: 0.45949
scores:
  nvd: 8.1
  cna: 8.1
  vendor: 5.9
ingestedAt: '2026-09-14T15:23:07.472Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T19:26:23.054440Z'
---

## Overview

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

lockd, nfsd: RCU-protect nlmsvc_ops dispatch

nlmsvc_ops is published by nfsd_lockd_init() and cleared by
nfsd_lockd_shutdown() with plain stores, while lockd dereferences
it unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer
targets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's
.text, so a stale load after rmmod nfsd results in either a NULL
deref or a module-text use-after-free.

Declare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear
via RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module
*owner field to nlmsvc_binding and pin the module across indirect
calls with try_module_get/module_put. When the binding is torn down,
fall back to fput() to avoid leaking struct file references.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89709.json)