---
id: CVE-2026-89694
title: 'nfsd: check client ownership when cancelling a copy-notify stateid'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: check client ownership when cancelling a copy-notify stateid

  On the OFFLOAD_CANCEL path (clp != NULL), manage_cpntf_state() freed the
  target cpntf state without …
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe:
  - CWE-639
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    88daaed26e17e1c7e851859b5bbb4f0e1ab6d0e9
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    81b2cfe767943922eca906a2a5af23a0ce5d0f35
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    6bba72b8ee68ad631b94bd439592cba46de54d7d
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    75268f6cfe26b09a7e4d3216367e87fe9e2a26aa
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    b1eca07303594ca27f5dc360a6946bd7e1f5b04c
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    b42dc26a14b4ad5d6daaada11ec4c70744141c25
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    d801906165cb5cc250d5cbe44935594e170be3e2
  - >-
    Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 <
    6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf
  - Linux 5.6
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:51:07.514Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89694'
references:
  - url: 'https://git.kernel.org/stable/c/88daaed26e17e1c7e851859b5bbb4f0e1ab6d0e9'
  - url: 'https://git.kernel.org/stable/c/81b2cfe767943922eca906a2a5af23a0ce5d0f35'
  - url: 'https://git.kernel.org/stable/c/6bba72b8ee68ad631b94bd439592cba46de54d7d'
  - url: 'https://git.kernel.org/stable/c/75268f6cfe26b09a7e4d3216367e87fe9e2a26aa'
  - url: 'https://git.kernel.org/stable/c/b1eca07303594ca27f5dc360a6946bd7e1f5b04c'
  - url: 'https://git.kernel.org/stable/c/b42dc26a14b4ad5d6daaada11ec4c70744141c25'
  - url: 'https://git.kernel.org/stable/c/d801906165cb5cc250d5cbe44935594e170be3e2'
  - url: 'https://git.kernel.org/stable/c/6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89694'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532327'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89694'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89694'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89694.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00216
epssPercentile: 0.12005
ingestedAt: '2026-09-14T15:23:07.449Z'
---

## Overview

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

nfsd: check client ownership when cancelling a copy-notify stateid

On the OFFLOAD_CANCEL path (clp != NULL), manage_cpntf_state() freed the
target cpntf state without checking ownership. The lookup key
st->si_opaque.so_id is allocated cyclically (guessable) and the embedded
clientid is the fixed per-net nn->s2s_cp_cl_id, so any authenticated
NFSv4.2 client could cancel and free another client's copy-notify
stateid.

Compare the creating clientid recorded in state->cp_p_clid against the
requesting client's cl_clientid and return nfserr_bad_stateid on a
mismatch instead of freeing the entry.

## Affected

- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < 88daaed26e17e1c7e851859b5bbb4f0e1ab6d0e9`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < 81b2cfe767943922eca906a2a5af23a0ce5d0f35`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < 6bba72b8ee68ad631b94bd439592cba46de54d7d`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < 75268f6cfe26b09a7e4d3216367e87fe9e2a26aa`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < b1eca07303594ca27f5dc360a6946bd7e1f5b04c`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < b42dc26a14b4ad5d6daaada11ec4c70744141c25`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < d801906165cb5cc250d5cbe44935594e170be3e2`
- `Linux >= ce0887ac96d35c7105090e166bb0807dc0a0e838 < 6bdbfab96e0cf25e5f57dac5c09dc1749751a4bf`
- `Linux 5.6`

## 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 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89694.json)