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.