High 7.5Published Feb 26, 2025

CVE-2025-21795NFSD: fix hang in nfsd4_shutdown_callback

Updated under an hour ago (Oct 26, 2026, 3:50 PM ET)

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Exploited in the last 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.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 67ef9e5fd737eab2495f2586df7e9ea30caa1b77 before abed68027ea3ab893ac85cc46a00e2e64a324239; from 26540b8940a2e21582afa61a6fb8af87310bac72 before efa8a261c575f816c7e79a87aeb3ef8a0bd6b221; 66af25799940b26efd41ea6e648f75c41a48a2c2 builds before 38d345f612503b850c2973e5a879f88e441b34d7; 66af25799940b26efd41ea6e648f75c41a48a2c2 builds before 23ad7797c74cd8f7f90617f1e59a8703e2b43908; from 66af25799940b26efd41ea6e648f75c41a48a2c2 before cedfbb92cf97a6bff3d25633001d9c44442ee854; from 66af25799940b26efd41ea6e648f75c41a48a2c2 before e88d2451cd42e025465d6b51fd716a47b0b3800d; 66af25799940b26efd41ea6e648f75c41a48a2c2 builds before 036ac2778f7b28885814c6fbc07e156ad1624d03; from 5.10.220 before 5.10.235; and 1 more ranges	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.5	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.5	CISA ADP
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name)	all versions	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.5	CISA ADP
linux linux_kernel linux:linux_kernel	from 5.10.220 before 5.10.235; from 5.15.154 before 5.15.179; from 5.19 before 6.1.129; from 6.2 before 6.6.79; from 6.7 before 6.12.16; from 6.13 before 6.13.4; 6.14; 6.14	NVD

References

References

https://git.kernel.org/stable/c/abed68027ea3ab893ac85cc46a00e2e64a324239	patch
https://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221	patch
https://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7	patch
https://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908	patch
https://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854	patch
https://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800d	patch
https://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03	patch
https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.