CVE-2026-89549

Status: UPDATED  |  Advisory ID: CVE-2026-89549

Key Details

Affected Products, Subsystems & Sectors

What to Know

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

sunrpc: route to a populated pool in svc_pool_for_cpu()

svc_set_num_threads() spreads the requested threads evenly across the

service's pools (base = nrservs / sv_nrpools). When a service runs

fewer threads than it has pools -- e.g. an nfsd configured with fewer

threads than the host has NUMA nodes while running in "pernode" or

"percpu" mode -- the trailing pools are left with no threads at all.

svc_xprt_enqueue() selects a pool from the CPU servicing the transport,

queues the transport on that pool's sp_xprts, and only wakes a thread

from the same pool. Each thread services exclusively its own pool, so a

transport that lands on a threadless pool is enqueued on sp_xprts and

never picked up: the connection hangs indefinitely.

Have svc_pool_for_cpu() skip pools that currently have no threads,

falling back to the next populated pool. This trades NUMA locality for

a guarantee that the work is actually serviced. sp_nrthreads is only

updated under the service mutex; the lockless read here is a best-effort

routing hint, so annotate it with data_race(). (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References