CVE-2026-89549

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the sunrpc component where connections can hang indefinitely. This occurs when a service, such as nfsd running in pernode or percpu mode, is configured with fewer threads than the host has NUMA nodes (Non-Uniform Memory Access), leaving some pools without threads. The svc xprt enqueue() function selects a pool based on the CPU servicing the transport and queues it on sp xprts, but since threads only service their own pool, a transport landing on a threadless pool is never processed. The fix involves modifying svc pool for cpu() to skip empty pools and route to the next populated one, prioritizing service guarantee over NUMA locality. The sp nrthreads variable is read as a best-effort routing hint and annotated with data race().

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.