smb: client: split cached_fid bitfields to avoid shared-byte RMW races

{
  "id": "40c0ca196b3292a04360c8be0861fde1cfd22b6c51398dded3a7989a5f38b514",
  "url": "https://osv.dev/vulnerability/CVE-2026-23230",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "smb: client: split cached_fid bitfields to avoid shared-byte RMW races",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: smb: client: split cached_fid bitfields to avoid shared-byte RMW races is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields.",
    "evidence": "osv:CVE-2026-23230",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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            "value": "6.1.164",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.6.125",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.19.1",
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        "affected_versions": []
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    "severity": "high",
    "structured": {
      "id": "CVE-2026-23230",
      "aliases": [
        "CVE-2026-23230"
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      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
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      "affected": [
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                  "fixed": "4cfa4c37dcbcfd70866e856200ed8a2894cac578"
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                  "fixed": "ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241"
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          "package": {
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            "ecosystem": "Linux"
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        }
      ],
      "modified": "2026-10-28T02:30:28.126695487Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-253495.html",
        "https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a",
        "https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828",
        "https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578",
        "https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b",
        "https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b",
        "https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23230.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-23230",
        "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/2026/23xxx/CVE-2026-23230.json"
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    "related_cves": [
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        "value": "CVE-2026-23230",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 494912,
  "published_at": "2026-02-18T14:53:34.078+00:00"
}