---
id: CVE-2026-89685
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix clock domain mismatch in clients_still_reclaiming()

  clients_still_reclaiming() computes a deadline from nn->boot_time
  (CLOCK_REALTIME, ~1.7 billion) but comp…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: fix clock domain mismatch in clients_still_reclaiming()

  clients_still_reclaiming() computes a deadline from nn->boot_time
  (CLOCK_REALTIME, ~1.7 billion) but comp…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1025
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <
    e92e80c5b043108029bc729b30d12c37158fb9cb
  - >-
    Linux >= 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <
    f9cec313efb2fd18d962aad738a4892bce806016
  - >-
    Linux >= 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <
    9843649196221152b6e5d138a3ce859bdaae1d96
  - >-
    Linux >= 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <
    09ea3eb9a518565f5bca386e81b993ed8825f5e8
  - Linux 5.6
published: '2026-09-11'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:25.203'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89685'
references:
  - url: 'https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e92e80c5b043108029bc729b30d12c37158fb9cb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89685.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89685'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532214'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89685'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89685'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89685.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00446
epssPercentile: 0.38212
scores:
  nvd: 7.5
  cna: 7.5
  vendor: 7
ingestedAt: '2026-09-14T15:23:07.473Z'
---

## Overview

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

nfsd: fix clock domain mismatch in clients_still_reclaiming()

clients_still_reclaiming() computes a deadline from nn->boot_time
(CLOCK_REALTIME, ~1.7 billion) but compares it against
ktime_get_boottime_seconds() (CLOCK_BOOTTIME, seconds since boot).
The comparison is always false — it would take ~54 years of uptime
for BOOTTIME to exceed the REALTIME-derived deadline.

This means any client can hold the server in grace indefinitely by
sending CLAIM_PREVIOUS OPEN requests, blocking all non-reclaim
operations for all other clients.

Add boot_time_bt (CLOCK_BOOTTIME) alongside the existing boot_time
and use it for the deadline computation. boot_time (CLOCK_REALTIME)
is preserved for its cl_boot clientid-nonce role.

## 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 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 8, Red Hat Enterprise Linux 9, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89685.json)