netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()

{
  "id": "94c9549222a766de6724aad520dab114aed4b6708e771fd8e4d88f8662b65033",
  "url": "https://osv.dev/vulnerability/CVE-2026-64216",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.",
    "evidence": "osv:CVE-2026-64216",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.106",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.34",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-64216",
      "aliases": [
        "CVE-2026-64216"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                {
                  "fixed": "dbe556972100fabb8e5a1b3d2163831ff07b1e8e"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64216.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.12.0"
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                  "fixed": "6.12.106"
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            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.34"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
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                {
                  "fixed": "7.0.11"
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64216.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:53.504506041Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/3866d015f33aeedf81338dd99154703bef33faef",
        "https://git.kernel.org/stable/c/6080fa3ecfbb4448a3b47368629534c09b6ec750",
        "https://git.kernel.org/stable/c/d4ae8dba90b89e7bb4d1045d1cb26afbaf13ee5c",
        "https://git.kernel.org/stable/c/dbe556972100fabb8e5a1b3d2163831ff07b1e8e",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64216.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64216",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64216.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64216",
        "evidence": "/id"
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    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 522242,
  "published_at": "2026-07-24T15:23:04.673+00:00"
}