CVE-2026-89685

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 38% of CVEs (scores of 2026-10-25)

Published

2026-09-11

Modified

2026-10-21

Record from

the NVD, synced 2026-10-22

References

• https://git.kernel.org/stable/c/04c3e4456fe76e8d7c94171009df3165c3262c51
• https://git.kernel.org/stable/c/09ea3eb9a518565f5bca386e81b993ed8825f5e8
• https://git.kernel.org/stable/c/9843649196221152b6e5d138a3ce859bdaae1d96
• https://git.kernel.org/stable/c/e92e80c5b043108029bc729b30d12c37158fb9cb
• https://git.kernel.org/stable/c/f9cec313efb2fd18d962aad738a4892bce806016

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