{"id":"CVE-2026-89658","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-89658","summary":"NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup\n\nnfs40_clean_admin_revoked() takes a stateid reference under\nclp->cl_lock, drops nn->client_lock, and calls\nnfsd4_drop_revoked_stid(), which dereferences the stateid's client\nthrough s->sc_client->cl_lock.  The stateid reference does not pin the\nclient, so a teardown racing the dropped lock can free the client\nwhile nfsd4_drop_revoked_stid() is still using it.\n\nThis cleanup runs from the laundromat, so a periodic sweep can race\nforce_expire_client() driven by a write to the clients/<id>/ctl file.\n\nSkip a client that is already expiring and otherwise pin it with\ncl_rpc_users under client_lock before dropping the lock, matching\nnfsd4_revoke_states().","published":"2026-09-11T19:45:46.857Z","modified":"2026-09-14T03:45:45.949907706Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.12.109"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55"},{"type":"WEB","url":"https://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89658.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89658"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-14T03:45:45.949907706Z"}}