---
id: CVE-2026-89484
title: 'lockd: fix NULL dereference on lockowner allocation failure'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  lockd: fix NULL dereference on lockowner allocation failure

  nlmclnt_locks_init_private() installs NLM file lock operations even when
  nlmclnt_find_lockowner() fails to …
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-476
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    6db5af172ccc3223c8f730a9a4212f6427feee3e
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    07adfbb3de7529f58ca708a97ead7fa4fdb71056
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    d662f7fc04fde305a27f304b3cd19b614d366839
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    51af080ca4e553256c59a75a877b9b4fff828311
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    4c7fc129db061c7daab841c4f3c342d894832362
  - Linux 2.6.12
published: '2026-09-11'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:47:36.031Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89484'
references:
  - url: 'https://git.kernel.org/stable/c/6db5af172ccc3223c8f730a9a4212f6427feee3e'
  - url: 'https://git.kernel.org/stable/c/07adfbb3de7529f58ca708a97ead7fa4fdb71056'
  - url: 'https://git.kernel.org/stable/c/d662f7fc04fde305a27f304b3cd19b614d366839'
  - url: 'https://git.kernel.org/stable/c/51af080ca4e553256c59a75a877b9b4fff828311'
  - url: 'https://git.kernel.org/stable/c/4c7fc129db061c7daab841c4f3c342d894832362'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89484.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89484'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532110'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89484'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89484'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89484.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00206
epssPercentile: 0.10584
ingestedAt: '2026-09-14T00:35:28.530Z'
---

## Overview

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

lockd: fix NULL dereference on lockowner allocation failure

nlmclnt_locks_init_private() installs NLM file lock operations even when
nlmclnt_find_lockowner() fails to allocate a lockowner. nlmclnt_proc()
then returns -ENOMEM, but the VFS still tears down the partially
initialized file_lock and calls locks_release_private().

That invokes nlmclnt_locks_release_private(), which dereferences
fl->fl_u.nfs_fl.owner and crashes because the owner was never installed.

Clear fl_ops before attempting to initialize the NLM private state, and
install the NLM lock operations only after a lockowner has been allocated
successfully.

## Affected

- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 6db5af172ccc3223c8f730a9a4212f6427feee3e`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 07adfbb3de7529f58ca708a97ead7fa4fdb71056`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d662f7fc04fde305a27f304b3cd19b614d366839`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 51af080ca4e553256c59a75a877b9b4fff828311`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4c7fc129db061c7daab841c4f3c342d894832362`
- `Linux 2.6.12`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89484.json)