nfsd: fix clock domain mismatch in clients_still_reclaiming()
Summary
| CVE | CVE-2026-89685 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-11 20:19:55 UTC |
| Updated | 2026-09-21 14:17:25 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.004460000 probability, percentile 0.381980000 (date 2026-09-22)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf e92e80c5b043108029bc729b30d12c37158fb9cb git | Not specified |
| CNA | Linux | Linux | affected 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf f9cec313efb2fd18d962aad738a4892bce806016 git | Not specified |
| CNA | Linux | Linux | affected 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf 9843649196221152b6e5d138a3ce859bdaae1d96 git | Not specified |
| CNA | Linux | Linux | affected 20b7d86f29d39e8ae19bb29c24ffee70dc385ddf 09ea3eb9a518565f5bca386e81b993ed8825f5e8 git | Not specified |
| CNA | Linux | Linux | affected 5.6 | Not specified |
| CNA | Linux | Linux | unaffected 5.6 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.51 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.4 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/e92e80c5b043108029bc729b30d12c37158fb9cb | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.