CVE-2026-80662
In the Linux kernel, the following vulnerability has been resolved:
cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size
The CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58 bytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing 64 bytes at offset 0x18. CXL_HEADERLOG_SIZE was defined as SZ_512, eight times the actual on-device size.
header_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the RAS capability iomap, overrunning the 88-byte mapping by 448 bytes.
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The cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE (512) bytes from its source. For the CPER caller the source is struct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a stack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes of kernel stack into the trace event ring buffer where userspace can read it via tracefs.
Set CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it, bringing all iomap readers into agreement on 16 dwords. Userspace tools such as rasdaemon have grown a dependency on the buggy 512-byte (128 u32) header_log layout in the cxl_aer_uncorrectable_error trace event. Add CXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event __array and its memcpy to preserve that ABI. Both callers now pass a zero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only the first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware; the remaining 112 u32s are zero-padded, keeping the 512-byte trace ring buffer layout intact.
[ dj: Replaced 64 with SZ_64 per RichardC ]
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Puntuación base: 7.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1005Data from Local Systemcollection90 % - Impacto secundario
T1552Unsecured Credentialscredential access88 %
AV:L/PR:L sin UI permite escalada local. El buffer overread filtra datos de kernel (stack memory) a través de tracefs accesible por usuario no privilegiado.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
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)
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{
"id": "CVE-2026-80662",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.2,
"exploitabilityScore": 1.8
}
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{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
"lessThan": "6fc1919a6f2ed541484dd1f6cd93374044f8fd3d",
"versionType": "git"
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{
"status": "affected",
"version": "2905cb5236cba63a5dc8a83752dcc31f3cc819f9",
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{
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"lessThan": "c268f949e219f9e179558e836f457f6c5fbec416",
"versionType": "git"
}
],
"programFiles": [
"drivers/cxl/core/ras.c",
"drivers/cxl/core/trace.h",
"drivers/cxl/cxl.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/cxl/core/ras.c",
"drivers/cxl/core/trace.h",
"drivers/cxl/cxl.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-08-28T08:16:51.397",
"references": [
{
"url": "https://git.kernel.org/stable/c/6fc1919a6f2ed541484dd1f6cd93374044f8fd3d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c268f949e219f9e179558e836f457f6c5fbec416",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fc5eb0962a5e50d64e711817cc24d67df2d90528",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size\n\nThe CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58\nbytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing\n64 bytes at offset 0x18. CXL_HEADERLOG_SIZE was defined as SZ_512,\neight times the actual on-device size.\n\nheader_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the\nRAS capability iomap, overrunning the 88-byte mapping by 448 bytes.\nThe cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE\n(512) bytes from its source. For the CPER caller the source is\nstruct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a\nstack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes\nof kernel stack into the trace event ring buffer where userspace can\nread it via tracefs.\n\nSet CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it,\nbringing all iomap readers into agreement on 16 dwords. Userspace tools\nsuch as rasdaemon have grown a dependency on the buggy 512-byte (128 u32)\nheader_log layout in the cxl_aer_uncorrectable_error trace event. Add\nCXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event\n__array and its memcpy to preserve that ABI. Both callers now pass a\nzero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only\nthe first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware;\nthe remaining 112 u32s are zero-padded, keeping the 512-byte trace ring\nbuffer layout intact.\n\n[ dj: Replaced 64 with SZ_64 per RichardC ]"
}
],
"lastModified": "2026-08-29T07:16:48.667",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}