FKIE_CVE-2026-23230
Vulnerability from fkie_nvd - Published: 2026-02-18 16:22 - Updated: 2026-04-02 15:16
Severity ?
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * |
{
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"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."
},
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"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": "2026-04-02T15:16:24.460",
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"published": "2026-02-18T16:22:32.807",
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}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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