https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-10-06T07:13:55.881526+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2025-21795 CVE-2025-21795 — NFSD: fix hang in nfsd4_shutdown_callback 2026-10-06T07:13:55.883577+00:00

Affected: Linux, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

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

NFSD: fix hang in nfsd4_shutdown_callback

If nfs4_client is in courtesy state then there is no point to send the callback. This causes nfsd4_shutdown_callback to hang since cl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP notifies NFSD that the connection was dropped.

This patch modifies nfsd4_run_cb_work to skip the RPC call if nfs4_client is in courtesy state.