{"id":"CVE-2025-21795","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix hang in nfsd4_shutdown_callback\n\nIf nfs4_client is in courtesy state then there is no point to send\nthe callback","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix hang in nfsd4_shutdown_callback\n\nIf nfs4_client is in courtesy state then there is no point to send\nthe callback. This causes nfsd4_shutdown_callback to hang …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.10.220, < 5.10.235","linux_kernel >= 5.15.154, < 5.15.179","linux_kernel >= 5.19, < 6.1.129","linux_kernel >= 6.2, < 6.6.79","linux_kernel >= 6.7, < 6.12.16","linux_kernel >= 6.13, < 6.13.4","linux_kernel = 6.14"],"patched":["linux_kernel 6.13.4"],"published":"2025-02-27","updated":"2026-07-14","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21795","references":[{"url":"https://git.kernel.org/stable/c/036ac2778f7b28885814c6fbc07e156ad1624d03","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/23ad7797c74cd8f7f90617f1e59a8703e2b43908","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/38d345f612503b850c2973e5a879f88e441b34d7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/abed68027ea3ab893ac85cc46a00e2e64a324239","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cedfbb92cf97a6bff3d25633001d9c44442ee854","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e88d2451cd42e025465d6b51fd716a47b0b3800d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/efa8a261c575f816c7e79a87aeb3ef8a0bd6b221","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-082556.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00643,"epssPercentile":0.49474,"ingestedAt":"2026-07-14T13:36:55.735Z","slug":"CVE-2025-21795","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix hang in nfsd4_shutdown_callback\n\nIf nfs4_client is in courtesy state then there is no point to send\nthe callback. This causes nfsd4_shutdown_callback to hang since\ncl_cb_inflight is not 0. This hang lasts about 15 minutes until TCP\nnotifies NFSD that the connection was dropped.\n\nThis patch modifies nfsd4_run_cb_work to skip the RPC call if\nnfs4_client is in courtesy state.\n\n## Affected\n\n- `linux_kernel >= 5.10.220, < 5.10.235`\n- `linux_kernel >= 5.15.154, < 5.15.179`\n- `linux_kernel >= 5.19, < 6.1.129`\n- `linux_kernel >= 6.2, < 6.6.79`\n- `linux_kernel >= 6.7, < 6.12.16`\n- `linux_kernel >= 6.13, < 6.13.4`\n- `linux_kernel = 6.14`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.13.4`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}