{"id":"CVE-2026-90236","summary":"NFSD: Release the export reference when reaping open stateids","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Release the export reference when reaping open stateids\n\nnfs4_put_stid() releases the svc_export tracked in\nnfs4_stid.sc_export, but free_ol_stateid_reaplist() frees open and\nlock stateids by calling -\u003esc_free() directly, bypassing that path.\nAn open stateid takes an sc_export reference in nfs4_open() and a\nlock stateid takes its own in init_lock_stateid(); both reach\nfree_ol_stateid_reaplist() through their normal teardown, the open\nstateid via release_open_stateid() and the lock stateid via\nnfsd4_release_lockowner(), each through put_ol_stateid_locked().\nThe reference is therefore never dropped, pinning the export and\nblocking unmount for the lifetime of the stateid.\n\nRelease sc_export in free_ol_stateid_reaplist() the way\nnfs4_put_stid() does. -\u003esc_free() runs once per stateid, and a\nstateid reaches free_ol_stateid_reaplist() or nfs4_put_stid() but\nnever both, so the reference is dropped exactly once. Revoked\nstateids reach this path with sc_export already cleared by\ndrop_stid_export(), so they are skipped rather than double-freed.\n\nnfs4_put_stid() itself read sc_export before acquiring cl_lock.\ndrop_stid_export() clears that field and releases the reference\nunder cl_lock, so a concurrent revocation could drop the export in\nthe window between the read and the final put, releasing the same\nreference twice. Read sc_export while cl_lock is held so the two\npaths serialize and the reference is released exactly once.","modified":"2026-09-19T03:47:25.437863752Z","published":"2026-09-17T16:07:41.898Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90236.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/6480bd703684ed3f760e9e36c4a699033c0806ae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7458727fd7cb79d09e5120b6fecc1ad11cdb0946"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90236.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90236"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ba0cde5dc81d214684b8ea0bd87414ba2f48fe02"},{"fixed":"7458727fd7cb79d09e5120b6fecc1ad11cdb0946"},{"fixed":"6480bd703684ed3f760e9e36c4a699033c0806ae"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90236.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.2.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90236.json"}}],"schema_version":"1.9.0"}