FKIE_CVE-2026-23230

Vulnerability from fkie_nvd - Published: 2026-02-18 16:22 - Updated: 2026-02-23 04:16
Severity ?
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: split cached_fid bitfields to avoid shared-byte RMW races\n\nis_open, has_lease and on_list are stored in the same bitfield byte in\nstruct cached_fid but are updated in different code paths that may run\nconcurrently. Bitfield assignments generate byte read\u2013modify\u2013write\noperations (e.g. `orb $mask, addr` on x86_64), so updating one flag can\nrestore stale values of the others.\n\nA possible interleaving is:\n    CPU1: load old byte (has_lease=1, on_list=1)\n    CPU2: clear both flags (store 0)\n    CPU1: RMW store (old | IS_OPEN) -\u003e reintroduces cleared bits\n\nTo avoid this class of races, convert these flags to separate bool\nfields."
    },
    {
      "lang": "es",
      "value": "Se ha resuelto la siguiente vulnerabilidad en el kernel de Linux:\n\nsmb: cliente: dividir los campos de bits de cached_fid para evitar condiciones de carrera RMW de bytes compartidos\n\nis_open, has_lease y on_list se almacenan en el mismo byte de campo de bits en la estructura cached_fid, pero se actualizan en diferentes rutas de c\u00f3digo que pueden ejecutarse concurrentemente. Las asignaciones de campos de bits generan operaciones de lectura-modificaci\u00f3n-escritura de bytes (p. ej., \u0027orb $mask, addr\u0027 en x86_64), por lo que al actualizar una bandera (flag) se puede restaurar valores obsoletos de las otras.\n\nUna posible intercalaci\u00f3n es:\n    CPU1: carga el byte antiguo (has_lease=1, on_list=1)\n    CPU2: borra ambas banderas (almacena 0)\n    CPU1: almacena RMW (old | IS_OPEN) -\u0026gt; reintroduce los bits borrados\n\nPara evitar esta clase de condiciones de carrera, hay que convertir estas banderas a campos bool separados."
    }
  ],
  "id": "CVE-2026-23230",
  "lastModified": "2026-02-23T04:16:01.873",
  "metrics": {},
  "published": "2026-02-18T16:22:32.807",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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