{"id":"CVE-2026-89658","title":"NFSD: Prevent client use-after-free during NFSv4.0 revoked-state cleanup","summary":"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_loc…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-825"],"vendor":"Linux","product":"Linux","affected":["Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < 0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519","Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < b413ec5b23e3445dc9c4f273116078e2d4747626","Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < 81cf7f1413862f87b078920c838460a6a88aa030","Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < 7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55","Linux 6.9"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:50:29.852Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89658","references":[{"url":"https://git.kernel.org/stable/c/0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519"},{"url":"https://git.kernel.org/stable/c/b413ec5b23e3445dc9c4f273116078e2d4747626"},{"url":"https://git.kernel.org/stable/c/81cf7f1413862f87b078920c838460a6a88aa030"},{"url":"https://git.kernel.org/stable/c/7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89658.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89658"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532130"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89658"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89658"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89658.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00617,"epssPercentile":0.49346,"scores":{"cna":9.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89658","body":"## Overview\n\nIn 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().\n\n## Affected\n\n- `Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < 0ae0d2b5c5a1b39c0b3c15d96b32a5b0c583d519`\n- `Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < b413ec5b23e3445dc9c4f273116078e2d4747626`\n- `Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < 81cf7f1413862f87b078920c838460a6a88aa030`\n- `Linux >= d688d8585e6bea5e4e37f7497feea93b6b0a469c < 7b4f8a1586c42d3afc3c0ac779af2db7ab1a5c55`\n- `Linux 6.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89658.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":224641,"id":"CVE-2026-89658","ts":1792401451227,"field":"cvss","old":"7","new":"9.8"},{"seq":224640,"id":"CVE-2026-89658","ts":1792401451227,"field":"severity","old":"high","new":"critical"},{"seq":205533,"id":"CVE-2026-89658","ts":1789576724335,"field":"cvss","old":"4.4","new":"7"},{"seq":205532,"id":"CVE-2026-89658","ts":1789576724335,"field":"severity","old":"medium","new":"high"},{"seq":202999,"id":"CVE-2026-89658","ts":1789403733292,"field":"cvss","old":"9.8","new":"4.4"},{"seq":202998,"id":"CVE-2026-89658","ts":1789403733292,"field":"severity","old":"critical","new":"medium"},{"seq":197803,"id":"CVE-2026-89658","ts":1789384320466,"field":"cvss","old":"4.4","new":"9.8"},{"seq":197802,"id":"CVE-2026-89658","ts":1789384320466,"field":"severity","old":"medium","new":"critical"},{"seq":183709,"id":"CVE-2026-89658","ts":1789356677051,"field":"cvss","old":"9.8","new":"4.4"},{"seq":183708,"id":"CVE-2026-89658","ts":1789356677051,"field":"severity","old":"critical","new":"medium"},{"seq":153514,"id":"CVE-2026-89658","ts":1789285351102,"field":"cvss","old":null,"new":"9.8"},{"seq":153513,"id":"CVE-2026-89658","ts":1789285351102,"field":"severity","old":"none","new":"critical"},{"seq":147756,"id":"CVE-2026-89658","ts":1789270212169,"field":"cvss","old":null,"new":"4.4"},{"seq":147755,"id":"CVE-2026-89658","ts":1789270212169,"field":"severity","old":"none","new":"medium"},{"seq":109518,"id":"CVE-2026-89658","ts":1789183732254,"field":"cvss","old":null,"new":"4.4"},{"seq":109517,"id":"CVE-2026-89658","ts":1789183732254,"field":"severity","old":"none","new":"medium"}]}