CVE-2025-21795
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.7% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel < 5.10.235
- Linux Kernel < 5.15.179
- Linux Kernel < 6.1.129
- Linux Kernel < 6.6.79
- Linux Kernel < 6.12.16
- Linux Kernel < 6.13.4
- Linux Kernel 6.14
Attack profile CVSS 3.1 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-21795.md and follow it. Check whether this project is affected by CVE-2025-21795. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03
- https://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908
- https://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7
- https://git.kernel.org/stable/c/abed68027ea3ab893ac85cc46a00e2e64a324239
- https://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854
- https://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800d
- https://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221
References
- https://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03
- https://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908
- https://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7
- https://git.kernel.org/stable/c/abed68027ea3ab893ac85cc46a00e2e64a324239
- https://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854
- https://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800d
- https://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221
- 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
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html