CVE-2026-46253
Estado: AnalizadaAlta (7.8)—
In the Linux kernel, the following vulnerability has been resolved:
pstore/ram: fix buffer overflow in persistent_ram_save_old()
persistent_ram_save_old() can be called multiple times for the same persistent_ram_zone (e.g., via ramoops_pstore_read -> ramoops_get_next_prz for PSTORE_TYPE_DMESG records).
Currently, the function only allocates prz->old_log when it is NULL, but it unconditionally updates prz->old_log_size to the current buffer size and then performs memcpy_fromio() using this new size. If the buffer size has grown since the first allocation (which can happen across different kernel boot cycles), this leads to:
Leer descripción completaMostrar menos
1. A heap buffer overflow (OOB write) in the memcpy_fromio() calls 2. A subsequent OOB read when ramoops_pstore_read() accesses the buffer using the incorrect (larger) old_log_size
The conditions are likely extremely hard to hit:
Free and reallocate the buffer when the new size differs from the previously allocated size. This ensures old_log always has sufficient space for the data being copied.
Detalles técnicos trazas, registros y código del informe original
The KASAN splat would look similar to:
BUG: KASAN: slab-out-of-bounds in ramoops_pstore_read+0x...
Read of size N at addr ... by task ...
0. Crash with a ramoops write of less-than-record-max-size bytes.
1. Reboot: ramoops registers, pstore_get_records(0) reads old crash,
allocates old_log with size X
2. Crash handler registered, timer started (if pstore_update_ms >= 0)
3. Oops happens (non-fatal, system continues)
4. pstore_dump() writes oops via ramoops_pstore_write() size Y (>X)
5. pstore_new_entry = 1, pstore_timer_kick() called
6. System continues running (not a panic oops)
7. Timer fires after pstore_update_ms milliseconds
8. pstore_timefunc() → schedule_work() → pstore_dowork() → pstore_get_records(1)
9. ramoops_get_next_prz() → persistent_ram_save_old()
10. buffer_size() returns Y, but old_log is X bytes
11. Y > X: memcpy_fromio() overflows heap
Requirements:
- a prior crash record exists that did not fill the record size
(almost impossible since the crash handler writes as much as it
can possibly fit into the record, capped by max record size and
the kmsg buffer almost always exceeds the max record size)
- pstore_update_ms >= 0 (disabled by default)
- Non-fatal oops (system survives)CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
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: 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).
🎯 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
T1059Command and Scripting Interpreterexecution75 % - Impacto secundario
T1499.004Application or System Exploitationimpact60 %
Buffer overflow en kernel de Linux (CWE-787) con acceso local y permisos de usuario (AV:L/PR:L). Permite ejecución de código de kernel tras desbordamiento de heap en persistent_ram_save_old().
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)
CWE
- CWE-787
Referencias
- https://git.kernel.org/stable/c/06d2c8bd108cea503f6f6e13e47495ed1085275f
- https://git.kernel.org/stable/c/2fa9a047c6a50ec80c3890dd623b85e237f0d1fd
- https://git.kernel.org/stable/c/4f73486ca822305c1cf5b8ebc0b53a6ab3801a81
- https://git.kernel.org/stable/c/5669645c052f235726a85f443769b6fc02f66762
- https://git.kernel.org/stable/c/58bda5a1d1ee98254383ef34f76b2c35140513ea
- https://git.kernel.org/stable/c/7cfe964e61c0ab667abd5f5b68e0acbf783efa4f
- https://git.kernel.org/stable/c/9a6fc69a570c0780834246d52c856cc3dbc2605f
- https://git.kernel.org/stable/c/cff0ef043e16feb5a02307c8f9d0117a96c5587c
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-46253",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"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": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "58bda5a1d1ee98254383ef34f76b2c35140513ea",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "06d2c8bd108cea503f6f6e13e47495ed1085275f",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "2fa9a047c6a50ec80c3890dd623b85e237f0d1fd",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "cff0ef043e16feb5a02307c8f9d0117a96c5587c",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "9a6fc69a570c0780834246d52c856cc3dbc2605f",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "4f73486ca822305c1cf5b8ebc0b53a6ab3801a81",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "7cfe964e61c0ab667abd5f5b68e0acbf783efa4f",
"versionType": "git"
},
{
"status": "affected",
"version": "201e4aca5aa179e6c69a4dcd36a3562e56b8d670",
"lessThan": "5669645c052f235726a85f443769b6fc02f66762",
"versionType": "git"
}
],
"programFiles": [
"fs/pstore/ram_core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.5"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.5",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.252",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.202",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.165",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.128",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.75",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.14",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.4",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/pstore/ram_core.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-06-03T18:16:26.170",
"references": [
{
"url": "https://git.kernel.org/stable/c/06d2c8bd108cea503f6f6e13e47495ed1085275f",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2fa9a047c6a50ec80c3890dd623b85e237f0d1fd",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4f73486ca822305c1cf5b8ebc0b53a6ab3801a81",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5669645c052f235726a85f443769b6fc02f66762",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/58bda5a1d1ee98254383ef34f76b2c35140513ea",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7cfe964e61c0ab667abd5f5b68e0acbf783efa4f",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9a6fc69a570c0780834246d52c856cc3dbc2605f",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cff0ef043e16feb5a02307c8f9d0117a96c5587c",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-787"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\npstore/ram: fix buffer overflow in persistent_ram_save_old()\n\npersistent_ram_save_old() can be called multiple times for the same\npersistent_ram_zone (e.g., via ramoops_pstore_read -> ramoops_get_next_prz\nfor PSTORE_TYPE_DMESG records).\n\nCurrently, the function only allocates prz->old_log when it is NULL,\nbut it unconditionally updates prz->old_log_size to the current buffer\nsize and then performs memcpy_fromio() using this new size. If the\nbuffer size has grown since the first allocation (which can happen\nacross different kernel boot cycles), this leads to:\n\n1. A heap buffer overflow (OOB write) in the memcpy_fromio() calls\n2. A subsequent OOB read when ramoops_pstore_read() accesses the buffer\n using the incorrect (larger) old_log_size\n\nThe KASAN splat would look similar to:\n BUG: KASAN: slab-out-of-bounds in ramoops_pstore_read+0x...\n Read of size N at addr ... by task ...\n\nThe conditions are likely extremely hard to hit:\n\n 0. Crash with a ramoops write of less-than-record-max-size bytes.\n 1. Reboot: ramoops registers, pstore_get_records(0) reads old crash,\n allocates old_log with size X\n 2. Crash handler registered, timer started (if pstore_update_ms >= 0)\n 3. Oops happens (non-fatal, system continues)\n 4. pstore_dump() writes oops via ramoops_pstore_write() size Y (>X)\n 5. pstore_new_entry = 1, pstore_timer_kick() called\n 6. System continues running (not a panic oops)\n 7. Timer fires after pstore_update_ms milliseconds\n 8. pstore_timefunc() → schedule_work() → pstore_dowork() → pstore_get_records(1)\n 9. ramoops_get_next_prz() → persistent_ram_save_old()\n 10. buffer_size() returns Y, but old_log is X bytes\n 11. Y > X: memcpy_fromio() overflows heap\n\n Requirements:\n - a prior crash record exists that did not fill the record size\n (almost impossible since the crash handler writes as much as it\n can possibly fit into the record, capped by max record size and\n the kmsg buffer almost always exceeds the max record size)\n - pstore_update_ms >= 0 (disabled by default)\n - Non-fatal oops (system survives)\n\nFree and reallocate the buffer when the new size differs from the\npreviously allocated size. This ensures old_log always has sufficient\nspace for the data being copied."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\npstore/ram: corrige desbordamiento de búfer en persistent_ram_save_old()\n\npersistent_ram_save_old() puede ser llamada múltiples veces para la misma persistent_ram_zone (por ejemplo, a través de ramoops_pstore_read -> ramoops_get_next_prz para registros PSTORE_TYPE_DMESG).\n\nActualmente, la función solo asigna prz->old_log cuando es NULL, pero actualiza incondicionalmente prz->old_log_size al tamaño de búfer actual y luego realiza memcpy_fromio() usando este nuevo tamaño. Si el tamaño del búfer ha crecido desde la primera asignación (lo que puede ocurrir en diferentes ciclos de arranque del kernel), esto lleva a:\n\n1. Un desbordamiento de búfer de pila (escritura OOB) en las llamadas a memcpy_fromio()\n2. Una lectura OOB posterior cuando ramoops_pstore_read() accede al búfer usando el old_log_size incorrecto (más grande)\n\nEl splat de KASAN se vería similar a:\n BUG: KASAN: slab-out-of-bounds en ramoops_pstore_read+0x...\n Lectura de tamaño N en la dirección ... por la tarea ...\n\nEs probable que las condiciones sean extremadamente difíciles de alcanzar:\n\n 0. Fallo con una escritura de ramoops de menos de record-max-size bytes.\n 1. Reinicio: ramoops se registra, pstore_get_records(0) lee el fallo antiguo, asigna old_log con tamaño X\n 2. Gestor de fallos registrado, temporizador iniciado (si pstore_update_ms >= 0)\n 3. Ocurre un oops (no fatal, el sistema continúa)\n 4. pstore_dump() escribe el oops a través de ramoops_pstore_write() tamaño Y (>X)\n 5. pstore_new_entry = 1, se llama a pstore_timer_kick()\n 6. El sistema continúa ejecutándose (no es un oops de pánico)\n 7. El temporizador se activa después de pstore_update_ms milisegundos\n 8. pstore_timefunc() ? schedule_work() ? pstore_dowork() ? pstore_get_records(1)\n 9. ramoops_get_next_prz() ? persistent_ram_save_old()\n 10. buffer_size() devuelve Y, pero old_log es de X bytes\n 11. Y > X: memcpy_fromio() desborda la pila\n\n Requisitos:\n - existe un registro de fallo anterior que no llenó el tamaño del registro (casi imposible ya que el gestor de fallos escribe tanto como puede caber en el registro, limitado por el tamaño máximo del registro y el búfer kmsg casi siempre excede el tamaño máximo del registro)\n - pstore_update_ms >= 0 (deshabilitado por defecto)\n - Oops no fatal (el sistema sobrevive)\n\nLibera y reasigna el búfer cuando el nuevo tamaño difiere del tamaño previamente asignado. Esto asegura que old_log siempre tenga espacio suficiente para los datos que se están copiando."
}
],
"lastModified": "2026-07-22T20:10:00.127",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "78DB234D-033A-4925-A93F-12808A20B8F3",
"versionEndExcluding": "5.10.252",
"versionStartIncluding": "3.5.1"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4002FC2B-1456-4666-B240-0EBF590C4671",
"versionEndExcluding": "5.15.202",
"versionStartIncluding": "5.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654",
"versionEndExcluding": "6.1.165",
"versionStartIncluding": "5.16"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2",
"versionEndExcluding": "6.6.128",
"versionStartIncluding": "6.2"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2",
"versionEndExcluding": "6.12.75",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "BF463CB7-1F58-4607-B847-77ED23E4B9B7",
"versionEndExcluding": "6.18.14",
"versionStartIncluding": "6.13"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "672A3E79-EC03-479D-8503-361DFBDC8092",
"versionEndExcluding": "6.19.4",
"versionStartIncluding": "6.19"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.5:-:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "71555F5B-DEB2-417A-8E33-90276DD2EFB8"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.5:rc4:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "2D13A502-2E47-4C09-A235-BA11BB91C1DE"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.5:rc5:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7F0CC423-9BE8-4B1C-8179-E3E24693BEAA"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.5:rc6:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F9893E78-1974-4ED0-B4DB-CD2F9161E61A"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:3.5:rc7:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1E1655C7-B886-47A0-AF2B-B54A25AA91FF"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}