nfsd: fix clock domain mismatch in clients_still_reclaiming() (CVE-2026-89685) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89685

nfsd: fix clock domain mismatch in clients_still_reclaiming()

Answer in brief

CVE-2026-89685 records a Unknown severity vulnerability in nfsd: fix clock domain mismatch in clients_still_reclaiming(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <f9cec313efb2fd18d962aad738a4892bce806016 \|\| >=20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <9843649196221152b6e5d138a3ce859bdaae1d96 \|\| >=20b7d86f29d39e8ae19bb29c24ffee70dc385ddf <09ea3eb9a518565f5bca386e81b993ed8825f5e8	f9cec313efb2fd18d962aad738a4892bce806016, 9843649196221152b6e5d138a3ce859bdaae1d96, 09ea3eb9a518565f5bca386e81b993ed8825f5e8
Linux/Linuxgeneric	5.6	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to f9cec313efb2fd18d962aad738a4892bce806016 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.