CVE-2026-23230

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.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a	Patch
https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828	Patch
https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578	Patch
https://git.kernel.org/stable/c/569fecc56bfe4df66f05734d67daef887746656b	Patch
https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b	Patch
https://git.kernel.org/stable/c/ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241	Patch
https://cert-portal.siemens.com/productcert/html/ssa-253495.html

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

History

19 Oct 2026, 19:17

Type	Values Removed	Values Added
CWE		CWE-362

Information

Published : 2026-02-18 16:22

Updated : 2026-10-19 19:17

NVD link : CVE-2026-23230

Mitre link : CVE-2026-23230

CVE.ORG link : CVE-2026-23230

JSON object : View

Products Affected

linux

linux_kernel

CWE

NVD-CWE-noinfo CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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[{"lang": "en", "value": "NVD-CWE-noinfo"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-362"}]}], "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) -> 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., 'orb $mask, addr' 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) -> reintroduce los bits borrados\n\nPara evitar esta clase de condiciones de carrera, hay que convertir estas banderas a campos bool separados."}], "lastModified": "2026-10-19T19:17:42.580", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8174AEBD-5EC1-4209-8FCF-6A75AA321999", "versionEndExcluding": "6.1.164", "versionStartIncluding": "6.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "74B70CDE-7B74-4280-BBCC-8889B8F28466", "versionEndExcluding": "6.6.125", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F1A7E514-FB3C-4B6B-8046-07D5A8F04644", "versionEndExcluding": "6.12.72", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7099A9EC-3D54-4424-BF01-7224EF88C79C", "versionEndExcluding": "6.18.11", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EE543C0D-A06B-414F-A403-CB1E088F261E", "versionEndExcluding": "6.19.1", "versionStartIncluding": "6.19"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}