CVE-2026-43455
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
mctp: route: hold key->lock in mctp_flow_prepare_output()
mctp_flow_prepare_output() checks key->dev and may call mctp_dev_set_key(), but it does not hold key->lock while doing so.
mctp_dev_set_key() and mctp_dev_release_key() are annotated with __must_hold(&key->lock), so key->dev access is intended to be serialized by key->lock. The mctp_sendmsg() transmit path reaches mctp_flow_prepare_output() via mctp_local_output() -> mctp_dst_output() without holding key->lock, so the check-and-set sequence is racy.
Example interleaving:
Now both devA and devB references were acquired, but only the final key->dev value is tracked for release. One reference can be lost, causing a resource leak as mctp_dev_release_key() would only decrease the reference on one dev.
Leer descripción completaMostrar menos
Fix by taking key->lock around the key->dev check and mctp_dev_set_key() call.
Detalles técnicos trazas, registros y código del informe original
CPU0 CPU1
---- ----
mctp_flow_prepare_output(key, devA)
if (!key->dev) // sees NULL
mctp_flow_prepare_output(
key, devB)
if (!key->dev) // still NULL
mctp_dev_set_key(devB, key)
mctp_dev_hold(devB)
key->dev = devB
mctp_dev_set_key(devA, key)
mctp_dev_hold(devA)
key->dev = devA // overwrites devBCVSS
- 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: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- 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).
Tecnologías afectadas (1)
CWE
- NVD-CWE-noinfo
Referencias
- https://git.kernel.org/stable/c/0695712f3a6f1a48915f95767cfb42077683dcdc
- https://git.kernel.org/stable/c/47893166bc5611ee9a20de6b8d2933b2320fb772
- https://git.kernel.org/stable/c/7d86aa41c073c4e7eb75fd2e674f1fd8f289728a
- https://git.kernel.org/stable/c/86f5334fcb48a5b611c33364ab52ca684d0f6d91
- https://git.kernel.org/stable/c/8d27d9b260dd19c1b519e1a13de6448f9984e30e
- https://git.kernel.org/stable/c/925a5ffd99cddd7a7e41d5ad120c7a2c6d50260f
JSON original (NVD)
Mostrar
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"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",
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmctp: route: hold key->lock in mctp_flow_prepare_output()\n\nmctp_flow_prepare_output() checks key->dev and may call\nmctp_dev_set_key(), but it does not hold key->lock while doing so.\n\nmctp_dev_set_key() and mctp_dev_release_key() are annotated with\n__must_hold(&key->lock), so key->dev access is intended to be\nserialized by key->lock. The mctp_sendmsg() transmit path reaches\nmctp_flow_prepare_output() via mctp_local_output() -> mctp_dst_output()\nwithout holding key->lock, so the check-and-set sequence is racy.\n\nExample interleaving:\n\n CPU0 CPU1\n ---- ----\n mctp_flow_prepare_output(key, devA)\n if (!key->dev) // sees NULL\n mctp_flow_prepare_output(\n key, devB)\n if (!key->dev) // still NULL\n mctp_dev_set_key(devB, key)\n mctp_dev_hold(devB)\n key->dev = devB\n mctp_dev_set_key(devA, key)\n mctp_dev_hold(devA)\n key->dev = devA // overwrites devB\n\nNow both devA and devB references were acquired, but only the final\nkey->dev value is tracked for release. One reference can be lost,\ncausing a resource leak as mctp_dev_release_key() would only decrease\nthe reference on one dev.\n\nFix by taking key->lock around the key->dev check and\nmctp_dev_set_key() call."
}
],
"lastModified": "2026-06-17T10:49:38.050",
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