CVE-2025-21795: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 5.10.220, before 5.10.235 (fixed in 5.10.235); from 5.15.154, before 5.15.179 (fixed in 5.15.179); from 5.19, before 6.1.129 (fixed in 6.1.129); from 6.2, before 6.6.79 (fixed in 6.6.79); from 6.7, before 6.12.16 (fixed in 6.12.16); from 6.13, before 6.13.4 (fixed in 6.13.4); …

Published 2025-02-27. Last modified 2026-07-30.