CVE-2026-64477
In the Linux kernel, the following vulnerability has been resolved:
x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled
The architecture updates the cpu_mask in a domain's header to track which online CPUs are associated with the domain. When this mask becomes empty the architecture initiates offline of the domain that includes calling on resctrl fs to offline the domain. If it is a monitoring domain in which LLC occupancy is tracked resctrl fs forces the limbo handler to clear all busy RMID state associated with the domain.
The limbo handler always reads the current event value associated with a busy RMID irrespective of it being checked as part of regular "is it still busy" check or whether it will be forced released anyway.
Leer descripción completaMostrar menos
When reading an RMID on a system with SNC enabled the "logical RMID" is converted to the "physical RMID" and this conversion requires the NUMA node ID of the resctrl monitoring domain that is in turn determined by querying the NUMA node ID of any CPU belonging to the monitoring domain.
When the monitoring domain is going offline its cpu_mask is empty causing the NUMA node ID query via cpu_to_node() to be done with "nr_cpu_ids" as argument resulting in an out-of-bounds access.
Refactor the limbo handler to skip reading the RMID when the RMID will just be forced to no longer be dirty in the domain anyway. Add a safety check to the architecture's RMID reader to protect against this scenario.
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.18%
- Percentil entre todas las CVEs puntuadas: 6
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64477",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "e13db55b5a0d447dea63cde772c1078405bbbf96",
"lessThan": "ebc300b7ee0c669fa76a7a8858298ff32e296103",
"versionType": "git"
},
{
"status": "affected",
"version": "e13db55b5a0d447dea63cde772c1078405bbbf96",
"lessThan": "be1567992417dc92133e74126de7a6066c825ac9",
"versionType": "git"
},
{
"status": "affected",
"version": "e13db55b5a0d447dea63cde772c1078405bbbf96",
"lessThan": "58c5ec23b1a238eb75cb0aba6f69d8f9e68ef0b2",
"versionType": "git"
},
{
"status": "affected",
"version": "e13db55b5a0d447dea63cde772c1078405bbbf96",
"lessThan": "fc16126cc11d9f507130bf84ab137ee0938c900e",
"versionType": "git"
}
],
"programFiles": [
"arch/x86/kernel/cpu/resctrl/monitor.c",
"fs/resctrl/monitor.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/kernel/cpu/resctrl/monitor.c",
"fs/resctrl/monitor.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-25T10:17:33.243",
"references": [
{
"url": "https://git.kernel.org/stable/c/58c5ec23b1a238eb75cb0aba6f69d8f9e68ef0b2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/be1567992417dc92133e74126de7a6066c825ac9",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ebc300b7ee0c669fa76a7a8858298ff32e296103",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fc16126cc11d9f507130bf84ab137ee0938c900e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled\n\nThe architecture updates the cpu_mask in a domain's header to track which\nonline CPUs are associated with the domain. When this mask becomes empty\nthe architecture initiates offline of the domain that includes calling\non resctrl fs to offline the domain. If it is a monitoring domain in\nwhich LLC occupancy is tracked resctrl fs forces the limbo handler to\nclear all busy RMID state associated with the domain.\n\nThe limbo handler always reads the current event value associated with a\nbusy RMID irrespective of it being checked as part of regular \"is it still\nbusy\" check or whether it will be forced released anyway. When reading an\nRMID on a system with SNC enabled the \"logical RMID\" is converted to the\n\"physical RMID\" and this conversion requires the NUMA node ID of the\nresctrl monitoring domain that is in turn determined by querying the NUMA\nnode ID of any CPU belonging to the monitoring domain.\n\nWhen the monitoring domain is going offline its cpu_mask is empty causing\nthe NUMA node ID query via cpu_to_node() to be done with \"nr_cpu_ids\" as\nargument resulting in an out-of-bounds access.\n\nRefactor the limbo handler to skip reading the RMID when the RMID will\njust be forced to no longer be dirty in the domain anyway. Add a safety\ncheck to the architecture's RMID reader to protect against this scenario."
}
],
"lastModified": "2026-08-17T05:17:53.410",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}