{"id":"CVE-2026-90236","state":"PUBLISHED","title":"NFSD: Release the export reference when reaping open stateids","description":"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 ->sc_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. ->sc_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.","publishedAt":"2026-09-17T16:07:41.898Z","updatedAt":"2026-10-19T09:00:12.535Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ba0cde5dc81d214684b8ea0bd87414ba2f48fe02","status":"affected","lessThan":"7458727fd7cb79d09e5120b6fecc1ad11cdb0946","versionType":"git"},{"version":"ba0cde5dc81d214684b8ea0bd87414ba2f48fe02","status":"affected","lessThan":"6480bd703684ed3f760e9e36c4a699033c0806ae","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.2","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]}],"references":["https://git.kernel.org/stable/c/7458727fd7cb79d09e5120b6fecc1ad11cdb0946","https://git.kernel.org/stable/c/6480bd703684ed3f760e9e36c4a699033c0806ae"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90236.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90236","state":"PUBLISHED","datePublished":"2026-09-17T16:07:41.898Z","dateUpdated":"2026-10-19T09:00:12.535Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.794Z"},"containers":{"cna":{"title":"NFSD: Release the export reference when reaping open stateids","descriptions":[{"lang":"en","value":"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 ->sc_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. ->sc_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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ba0cde5dc81d214684b8ea0bd87414ba2f48fe02","status":"affected","lessThan":"7458727fd7cb79d09e5120b6fecc1ad11cdb0946","versionType":"git"},{"version":"ba0cde5dc81d214684b8ea0bd87414ba2f48fe02","status":"affected","lessThan":"6480bd703684ed3f760e9e36c4a699033c0806ae","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.2","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/nfsd/nfs4state.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/7458727fd7cb79d09e5120b6fecc1ad11cdb0946"},{"url":"https://git.kernel.org/stable/c/6480bd703684ed3f760e9e36c4a699033c0806ae"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:00:12.535Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.2","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.2","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}