CVE-2022-49761

Estado: AnalizadaAlta (7.8)—

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

btrfs: always report error in run_one_delayed_ref()

Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but if end users hit such problem, there will be no chance that btrfs_debug() is enabled. This can lead to very little useful info for debugging.

This patch will:

- Replace the btrfs_debug() with btrfs_err()

This error should only be triggered at most once.

As if run_one_delayed_ref() failed, we trigger the error message, then causing the call chain to error out:

And we will abort the current transaction in btrfs_run_delayed_refs(). If we have to run delayed refs for the abort transaction, run_one_delayed_ref() will just cleanup the refs and do nothing, thus no new error messages would be output.

Detalles técnicos trazas, registros y código del informe original

- Add extra info for error reporting
  Including:
  * logical bytenr
  * num_bytes
  * type
  * action
  * ref_mod

- Move the error reporting into run_one_delayed_ref()
  This is to avoid use-after-free, the @node can be freed in the caller.

btrfs_run_delayed_refs()
`- btrfs_run_delayed_refs()
   `- btrfs_run_delayed_refs_for_head()
      `- run_one_delayed_ref()

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation75 %
Impacto principalT1059 Command and Scripting Interpreterexecution60 %
Impacto secundarioT1499.004 Application or System Exploitationimpact55 %

Vulnerabilidad use-after-free (CWE-416) con AV:L/PR:L permite escalada de privilegios en kernel Linux. Ejecución de código y DoS (crash de transacciones) al fallar referencias retrasadas.

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 Privileged Account Management Limit Software Installation Filter Network Traffic

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-416

Referencias

JSON original (NVD)

Mostrar

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      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: siempre informa el error en run_one_delayed_ref() Actualmente tenemos un btrfs_debug() para el fallo de run_one_delayed_ref(), pero si los usuarios finales se encuentran con dicho problema, no habrá ninguna posibilidad de que btrfs_debug() esté habilitado. Esto puede llevar a muy poca información útil para la depuración. Este parche hará lo siguiente: - Agregar información adicional para el informe de errores Incluyendo: * byte lógico * num_bytes * tipo * acción * ref_mod - Reemplazar btrfs_debug() con btrfs_err() - Mover el informe de errores a run_one_delayed_ref() Esto es para evitar el use-after-free, el @nodo se puede liberar en el llamador. Este error solo debe activarse como máximo una vez. Como si run_one_delayed_ref() fallara, se genera un mensaje de error, lo que provoca que la cadena de llamadas genere un error: btrfs_run_delayed_refs() `- btrfs_run_delayed_refs() `- btrfs_run_delayed_refs_for_head() `- run_one_delayed_ref(). Abortaremos la transacción actual en btrfs_run_delayed_refs(). Si necesitamos ejecutar referencias retrasadas para la transacción abortada, run_one_delayed_ref() simplemente las limpiará y no hará nada, por lo que no se generarán nuevos mensajes de error."
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