{"id":"CVE-2026-89692","title":"nfsd: clear CALLBACK_RUNNING on failed delegation recall queue","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: clear CALLBACK_RUNNING on failed delegation recall queue\n\nnfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit\nat entry to serialize recall wor…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-911"],"vendor":"Linux","product":"Linux","affected":["Linux >= 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 < b137930ee52e3ef38915a3511d4c070463b63a32","Linux >= 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 < cb2d0c4d1b3d301d042ed61365eaa8cb0141a254","Linux >= 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 < b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96","Linux 6.15"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:51:05.555Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89692","references":[{"url":"https://git.kernel.org/stable/c/b137930ee52e3ef38915a3511d4c070463b63a32"},{"url":"https://git.kernel.org/stable/c/cb2d0c4d1b3d301d042ed61365eaa8cb0141a254"},{"url":"https://git.kernel.org/stable/c/b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89692.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89692"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532481"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89692"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89692"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89692.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00609,"epssPercentile":0.48945,"scores":{"cna":7.5,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89692","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: clear CALLBACK_RUNNING on failed delegation recall queue\n\nnfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit\nat entry to serialize recall work, then calls nfsd4_run_cb() to queue\nthe recall.  When the queue attempt fails the refcount bump is undone,\nbut the RUNNING bit is left set.  The only site that clears the bit is\nnfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the\nworkqueue and is therefore unreachable when nothing was queued.\n\nThe bit becomes a permanent latch on dp->dl_recall.cb_flags: every\nsubsequent break_lease() on the same delegation hits the early-return\nguard in nfsd_break_one_deleg() and silently skips the recall, so the\ndelegation is never broken and the conflicting open or lock stalls.\n\nFix by clearing NFSD4_CALLBACK_RUNNING on the !queued branch alongside\nthe refcount_dec.\n\n## Affected\n\n- `Linux >= 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 < b137930ee52e3ef38915a3511d4c070463b63a32`\n- `Linux >= 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 < cb2d0c4d1b3d301d042ed61365eaa8cb0141a254`\n- `Linux >= 1054e8ffc5c492f341bdf1888b882f1d163dd3d8 < b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96`\n- `Linux 6.15`\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 OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89692.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":224613,"id":"CVE-2026-89692","ts":1792401437546,"field":"cvss","old":"5.5","new":"7.5"},{"seq":224612,"id":"CVE-2026-89692","ts":1792401437546,"field":"severity","old":"medium","new":"high"},{"seq":203857,"id":"CVE-2026-89692","ts":1789490210198,"field":"cvss","old":"5.3","new":"5.5"},{"seq":202818,"id":"CVE-2026-89692","ts":1789403732489,"field":"cvss","old":"7.5","new":"5.3"},{"seq":202817,"id":"CVE-2026-89692","ts":1789403732489,"field":"severity","old":"high","new":"medium"},{"seq":197724,"id":"CVE-2026-89692","ts":1789384318557,"field":"cvss","old":"5.3","new":"7.5"},{"seq":197723,"id":"CVE-2026-89692","ts":1789384318557,"field":"severity","old":"medium","new":"high"},{"seq":183351,"id":"CVE-2026-89692","ts":1789356675001,"field":"cvss","old":"7.5","new":"5.3"},{"seq":183350,"id":"CVE-2026-89692","ts":1789356675001,"field":"severity","old":"high","new":"medium"},{"seq":153574,"id":"CVE-2026-89692","ts":1789285351340,"field":"cvss","old":null,"new":"7.5"},{"seq":153573,"id":"CVE-2026-89692","ts":1789285351340,"field":"severity","old":"none","new":"high"},{"seq":147143,"id":"CVE-2026-89692","ts":1789270196657,"field":"cvss","old":null,"new":"5.3"},{"seq":147142,"id":"CVE-2026-89692","ts":1789270196657,"field":"severity","old":"none","new":"medium"},{"seq":108894,"id":"CVE-2026-89692","ts":1789183729439,"field":"cvss","old":null,"new":"5.3"},{"seq":108893,"id":"CVE-2026-89692","ts":1789183729439,"field":"severity","old":"none","new":"medium"}]}