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CVE-2024-49854

Estado: ModificadaAlta (7.8)—

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

block, bfq: fix uaf for accessing waker_bfqq after splitting

After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe.

Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

CVSS

Probabilidad de explotación (EPSS)

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.

Vector AV:L/AC:L/PR:L: requiere acceso local con privilegios de usuario. CWE-416 (use-after-free) en el kernel Linux puede permitir escalada a través de manipulación de estructuras de memoria, facilitando ejecución de código arbitrario con privilegios elevados.

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 PreventionThreat Intelligence ProgramRestrict Web-Based ContentPrivileged Account ManagementLimit Software InstallationBehavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

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      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock, bfq: fix uaf for accessing waker_bfqq after splitting\n\nAfter commit 42c306ed7233 (\"block, bfq: don't break merge chain in\nbfq_split_bfqq()\"), if the current procress is the last holder of bfqq,\nthe bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and\nthen access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq\nmay in the merge chain of bfqq, hence just recored waker_bfqq is still\nnot safe.\n\nFix the problem by adding a helper bfq_waker_bfqq() to check if\nbfqq->waker_bfqq is in the merge chain, and current procress is the only\nholder."
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      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bloqueo, bfq: arregle uaf por acceder waker_bfqq despues de separar Después de el commit 42c306ed7233 (\"block, bfq: don't break merge chain in bfq_split_bfqq()\"), si el proceso actual es el último contenedor de bfqq, el bfqq se puede liberar después de bfq_split_bfqq(). Por lo tanto, grabar el bfqq y luego acceder a bfqq->waker_bfqq puede activar UAF. Además, waker_bfqq puede estar en la cadena de fusión de bfqq, por lo tanto, grabar solo waker_bfqq sigue sin ser seguro. Solucione el problema añadiendo un ayudante bfq_waker_bfqq() para comprobar si bfqq->waker_bfqq está en la cadena de fusión y el proceso actual es el único contenedor."
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