FKIE_CVE-2026-23230
Vulnerability from fkie_nvd - Published: 2026-02-18 16:22 - Updated: 2026-10-19 19:17
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/
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 | * |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/smb/client/cached_dir.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "569fecc56bfe4df66f05734d67daef887746656b",
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"versionType": "git"
},
{
"lessThan": "4386f6af8aaedd0c5ad6f659b40cadcc8f423828",
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"versionType": "git"
},
{
"lessThan": "3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a",
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"versionType": "git"
},
{
"lessThan": "c4b9edd55987384a1f201d3d07ff71e448d79c1b",
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"versionType": "git"
},
{
"lessThan": "4cfa4c37dcbcfd70866e856200ed8a2894cac578",
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"versionType": "git"
},
{
"lessThan": "ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241",
"status": "affected",
"version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/smb/client/cached_dir.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"lessThan": "6.1",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.164",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.125",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.72",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.1",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"affectedData": [
{
"defaultStatus": "unknown",
"product": "RUGGEDCOM RST2428P",
"vendor": "Siemens",
"versions": [
{
"lessThan": "V4.0",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "8174AEBD-5EC1-4209-8FCF-6A75AA321999",
"versionEndExcluding": "6.1.164",
"versionStartIncluding": "6.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "74B70CDE-7B74-4280-BBCC-8889B8F28466",
"versionEndExcluding": "6.6.125",
"versionStartIncluding": "6.2",
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},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "F1A7E514-FB3C-4B6B-8046-07D5A8F04644",
"versionEndExcluding": "6.12.72",
"versionStartIncluding": "6.7",
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{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "7099A9EC-3D54-4424-BF01-7224EF88C79C",
"versionEndExcluding": "6.18.11",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "EE543C0D-A06B-414F-A403-CB1E088F261E",
"versionEndExcluding": "6.19.1",
"versionStartIncluding": "6.19",
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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": "2026-10-19T19:17:42.580",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
},
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-23230",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-10-16T15:06:47.736511Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-02-18T16:22:32.807",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"url": "https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828"
},
{
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"url": "https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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],
"url": "https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-253495.html"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
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],
"source": "nvd@nist.gov",
"type": "Primary"
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{
"description": [
{
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"value": "CWE-362"
}
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
]
}
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Nomenclature
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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