CVE-2025-21795

HIGH

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.

CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Published: 2/27/2025Modified: 7/30/2026

Related Intelligence (1)

CRITICALAi

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

<p><a href="https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-209-04.json"><strong>View CSAF</strong></a></p> <h2>Summary</h2> <p><strong>Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.6 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens is preparing fix versions and recommend

CVE-2021-41617CVE-2023-28531
CISA Advisories

References (12)

https://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03Patchhttps://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908Patchhttps://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7Patchhttps://git.kernel.org/stable/c/abed68027ea3ab893ac85cc46a00e2e64a324239Patchhttps://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854Patchhttps://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800dPatchhttps://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221Patchhttps://lists.debian.org/debian-lts-announce/2025/03/msg00028.htmlhttps://lists.debian.org/debian-lts-announce/2025/05/msg00030.htmlhttps://cert-portal.siemens.com/productcert/html/ssa-019113.htmlhttps://cert-portal.siemens.com/productcert/html/ssa-082556.htmlhttps://cert-portal.siemens.com/productcert/html/ssa-265688.html