CVE-2026-64124

Estado: AnalizadaAlta (8.8)—

In the Linux kernel, the following vulnerability has been resolved:

net: devmem: reject dma-buf bind with non-page-aligned size or SG length

net_devmem_bind_dmabuf() trusts dmabuf->size and sg_dma_len() to be PAGE_SIZE multiples without checking:

dma-buf does not require page-aligned sizes, so the bind path has to enforce what its own indexing assumes. Reject both with -EINVAL.

The size check is TX-only (only tx_vec is sized off dmabuf->size); the SG-length check covers both directions.

Detalles técnicos trazas, registros y código del informe original

  - tx_vec is sized dmabuf->size / PAGE_SIZE, and
    net_devmem_get_niov_at() only bounds-checks virt_addr < dmabuf->size
    before indexing tx_vec[virt_addr / PAGE_SIZE]. With size =
    N*PAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base =
    N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past.

  - owner->area.num_niovs = len / PAGE_SIZE while gen_pool_add_owner()
    covers the full byte len, so a non-page-multiple non-final sg
    desyncs num_niovs from the gen_pool region for every later sg, on
    both RX and TX.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Puntuación base: 8.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.17%
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).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1059 Command and Scripting Interpreterexecution75 %
Impacto secundarioT1565.001 Stored Data Manipulationimpact70 %

Vulnerabilidad local (AV:L, PR:L) sin interacción que permite escalada mediante lectura fuera de límites en tx_vec y desincronización de gen_pool, logrando ejecución de código con privilegios elevados o manipulación de memoria.

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Restrict File and Directory Permissions Privileged Account Management Remote Data Storage

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: devmem: reject dma-buf bind with non-page-aligned size or SG length\n\nnet_devmem_bind_dmabuf() trusts dmabuf->size and sg_dma_len() to be\nPAGE_SIZE multiples without checking:\n\n  - tx_vec is sized dmabuf->size / PAGE_SIZE, and\n    net_devmem_get_niov_at() only bounds-checks virt_addr < dmabuf->size\n    before indexing tx_vec[virt_addr / PAGE_SIZE]. With size =\n    N*PAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base =\n    N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past.\n\n  - owner->area.num_niovs = len / PAGE_SIZE while gen_pool_add_owner()\n    covers the full byte len, so a non-page-multiple non-final sg\n    desyncs num_niovs from the gen_pool region for every later sg, on\n    both RX and TX.\n\ndma-buf does not require page-aligned sizes, so the bind path has to\nenforce what its own indexing assumes. Reject both with -EINVAL.\n\nThe size check is TX-only (only tx_vec is sized off dmabuf->size); the\nSG-length check covers both directions."
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