{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-89670",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-89670",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-09-11T19:45:55.846Z",
    "updatedAt": "2026-10-19T08:50:43.628Z",
    "importedAt": "2026-10-24T01:58:35.090Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "nfsd: hold rcu across localio cmpxchg retry",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: hold rcu across localio cmpxchg retry\n\nnfsd_file objects are freed via call_rcu (filecache.c:296), and\nnfsd_file_slab is created without SLAB_TYPESAFE_BY_RCU\n(KMEM_CACHE(nfsd_file, 0) at filecache.c:789), so the slab page\nbacking a freed nfsd_file becomes freely reclaimable once the RCU\ngrace period elapses.\n\nThe again: retry block in nfsd_open_local_fh() loads a pointer with\ncmpxchg and then calls nfsd_file_get(new) (which is\nrefcount_inc_not_zero) without holding rcu_read_lock. The sole caller\nnfs_open_local_fh() drops rcu_read_lock before invoking this helper,\nso no outer reader-side critical section covers the load.\n\n    CPU 0 (nfsd_open_local_fh)        CPU 1 (nfsd_file_put_local)\n    -----                             -----\n    new = cmpxchg(pnf, NULL, ...)\n                                      nf = xchg(pnf, NULL)\n                                      nfsd_file_put(nf)\n                                        last ref -> call_rcu()\n                                      /* grace period elapses;\n                                         slab page recycled */\n    nfsd_file_get(new)\n      refcount_inc_not_zero(&new->nf_ref)\n      /* operates on recycled memory */\n\nA non-zero word at the nf_ref offset of the recycled object makes the\nrefcount bump appear to succeed, and the caller then dereferences\nnew->nf_net and new->nf_file out of freed memory.\n\nFix by taking rcu_read_lock() immediately before the cmpxchg and\nreleasing it on all three exits of the if (new) block: the goto-again\nretry, the lost-race cleanup path, and the install-succeeded path.\nnfsd_file_put() and nfsd_net_put() stay outside the RCU section so\nthey remain free to block.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "e6f7e1487ab528a6c653bd0d42812ff2942846cd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "763c0bad872368304db718f79af7e93048885c67"
            },
            {
              "version": "e6f7e1487ab528a6c653bd0d42812ff2942846cd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "559570f91a7d4d199a72105e4980bef791f4cbf1"
            },
            {
              "version": "e6f7e1487ab528a6c653bd0d42812ff2942846cd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "58884694978a3d7d111edb433d7fd6a6c5af2f34"
            },
            {
              "version": "986a21ace186433e0397a59491646edad8c8d636",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6.15.3",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.16"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.16",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.16"
            },
            {
              "version": "6.18.50",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}