CVE-2025-38055
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix segfault with PEBS-via-PT with sample_freq
Currently, using PEBS-via-PT with a sample frequency instead of a sample period, causes a segfault. For example:
That happens because intel_pmu_pebs_event_update_no_drain() assumes all the pebs_enabled bits represent counter indexes, which is not always the case. In this particular case, bits 60 and 61 are set for PEBS-via-PT purposes.
The behaviour of PEBS-via-PT with sample frequency is questionable because although a PMI is generated (PEBS_PMI_AFTER_EACH_RECORD), the period is not adjusted anyway.
Leer descripción completaMostrar menos
Putting that aside, fix intel_pmu_pebs_event_update_no_drain() by passing the mask of counter bits instead of 'size'. Note, prior to the Fixes commit, 'size' would be limited to the maximum counter index, so the issue was not hit.
Detalles técnicos trazas, registros y código del informe original
BUG: kernel NULL pointer dereference, address: 0000000000000195
<NMI>
? __die_body.cold+0x19/0x27
? page_fault_oops+0xca/0x290
? exc_page_fault+0x7e/0x1b0
? asm_exc_page_fault+0x26/0x30
? intel_pmu_pebs_event_update_no_drain+0x40/0x60
? intel_pmu_pebs_event_update_no_drain+0x32/0x60
intel_pmu_drain_pebs_icl+0x333/0x350
handle_pmi_common+0x272/0x3c0
intel_pmu_handle_irq+0x10a/0x2e0
perf_event_nmi_handler+0x2a/0x50CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.19%
- Percentil entre todas las CVEs puntuadas: 8
- 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).
Tecnologías afectadas (1)
CWE
- CWE-476
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-38055",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1.8
}
]
},
"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": "722e42e45c2f1c6d1adec7813651dba5139f52f4",
"lessThan": "ca51db23166767a8445deb8331c9b8d5205d9287",
"versionType": "git"
},
{
"status": "affected",
"version": "722e42e45c2f1c6d1adec7813651dba5139f52f4",
"lessThan": "0b1874a5b1173fbcb2185ab828f4c33d067e551e",
"versionType": "git"
},
{
"status": "affected",
"version": "722e42e45c2f1c6d1adec7813651dba5139f52f4",
"lessThan": "99bcd91fabada0dbb1d5f0de44532d8008db93c6",
"versionType": "git"
},
{
"status": "affected",
"version": "a9d6d466bcf0621a872e1052bc40e4c6f0541b8d",
"versionType": "git"
},
{
"status": "affected",
"version": "6.10.5",
"lessThan": "6.11",
"versionType": "semver"
}
],
"programFiles": [
"arch/x86/events/intel/ds.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": "6.12.31",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.14.9",
"versionType": "semver",
"lessThanOrEqual": "6.14.*"
},
{
"status": "unaffected",
"version": "6.15",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/events/intel/ds.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-06-18T10:15:38.213",
"references": [
{
"url": "https://git.kernel.org/stable/c/0b1874a5b1173fbcb2185ab828f4c33d067e551e",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/99bcd91fabada0dbb1d5f0de44532d8008db93c6",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ca51db23166767a8445deb8331c9b8d5205d9287",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/x86/intel: Fix segfault with PEBS-via-PT with sample_freq\n\nCurrently, using PEBS-via-PT with a sample frequency instead of a sample\nperiod, causes a segfault. For example:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000195\n <NMI>\n ? __die_body.cold+0x19/0x27\n ? page_fault_oops+0xca/0x290\n ? exc_page_fault+0x7e/0x1b0\n ? asm_exc_page_fault+0x26/0x30\n ? intel_pmu_pebs_event_update_no_drain+0x40/0x60\n ? intel_pmu_pebs_event_update_no_drain+0x32/0x60\n intel_pmu_drain_pebs_icl+0x333/0x350\n handle_pmi_common+0x272/0x3c0\n intel_pmu_handle_irq+0x10a/0x2e0\n perf_event_nmi_handler+0x2a/0x50\n\nThat happens because intel_pmu_pebs_event_update_no_drain() assumes all the\npebs_enabled bits represent counter indexes, which is not always the case.\nIn this particular case, bits 60 and 61 are set for PEBS-via-PT purposes.\n\nThe behaviour of PEBS-via-PT with sample frequency is questionable because\nalthough a PMI is generated (PEBS_PMI_AFTER_EACH_RECORD), the period is not\nadjusted anyway.\n\nPutting that aside, fix intel_pmu_pebs_event_update_no_drain() by passing\nthe mask of counter bits instead of 'size'. Note, prior to the Fixes\ncommit, 'size' would be limited to the maximum counter index, so the issue\nwas not hit."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: perf/x86/intel: Corrección de una falla de segmentación con PEBS-via-PT con sample_freq. Actualmente, usar PEBS-via-PT con una frecuencia de muestreo en lugar de un periodo de muestreo provoca una falla de segmentación. Por ejemplo: Error: Desreferencia de puntero nulo del kernel, dirección: 0000000000000195 ? __die_body.cold+0x19/0x27 ? page_fault_oops+0xca/0x290 ? exc_page_fault+0x7e/0x1b0 ? asm_exc_page_fault+0x26/0x30 ? intel_pmu_pebs_event_update_no_drain+0x40/0x60 ? intel_pmu_pebs_event_update_no_drain+0x32/0x60 intel_pmu_drain_pebs_icl+0x333/0x350 handle_pmi_common+0x272/0x3c0 intel_pmu_handle_irq+0x10a/0x2e0 perf_event_nmi_handler+0x2a/0x50 Esto sucede porque intel_pmu_pebs_event_update_no_drain() asume que todos los bits pebs_enabled representan índices de contador, lo que no siempre es el caso. En este caso particular, los bits 60 y 61 se establecen para fines de PEBS a través de PT. El comportamiento de PEBS a través de PT con frecuencia de muestreo es cuestionable porque, aunque se genera un PMI (PEBS_PMI_AFTER_EACH_RECORD), el período no se ajusta de todos modos. Dejando eso de lado, corrija intel_pmu_pebs_event_update_no_drain() pasando la máscara de bits del contador en lugar de 'size'. Tenga en cuenta que, antes de el commit de las correcciones, 'size' estaba limitado al índice máximo del contador, por lo que el problema no se solucionó."
}
],
"lastModified": "2026-06-17T09:15:57.867",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7574F099-495B-4736-9856-4051B64518D7",
"versionEndExcluding": "6.12.31",
"versionStartIncluding": "6.10.5"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A9B72DD1-715C-4101-A720-1C8D70044C06",
"versionEndExcluding": "6.14.9",
"versionStartIncluding": "6.13"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8D465631-2980-487A-8E65-40AE2B9F8ED1"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4C9D071F-B28E-46EC-AC61-22B913390211"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "13FC0DDE-E513-465E-9E81-515702D49B74"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8C7B5B0E-4EEB-48F5-B4CF-0935A7633845"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "2D240580-3048-49B2-9E27-F115A9DF8224"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.15:rc6:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "90320558-E553-4EF5-8A0B-0F5D20113BD2"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}