CVE-2025-21795
NFSD: fix hang in nfsd4_shutdown_callback
Vexday Risk Score
3Low
SSVC decision (CISA)
Track
No exploitation signal → monitor
CVSS —EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —
Lifecycle
27 Feb 2025Published on NVD
Recommendation: Monitor — no exploitation signal at the moment.
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 · LinuxReferences
https://cert-portal.siemens.com/productcert/html/ssa-082556.htmlhttps://cert-portal.siemens.com/productcert/html/ssa-265688.htmlhttps://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03https://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908https://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7https://git.kernel.org/stable/c/abed68027ea3ab893ac85cc46a00e2e64a324239https://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854https://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800dhttps://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221https://lists.debian.org/debian-lts-announce/2025/03/msg00028.htmlhttps://lists.debian.org/debian-lts-announce/2025/05/msg00030.html