CVE-2026-98694
Estado: RecibidaSin puntuar—
Gravedad—Sin puntuar
Probabilidad de explotación0.17 %mayor que el 6 % de las CVE
Explotación activaNono figura en el catálogo de CISA
Exploit públicoNo conocidosin código público localizado
En el kernel de Linux se ha resuelto la siguiente vulnerabilidad:
thunderbolt: Corregir use-after-free detectado por KASAN cuando se cancela una solicitud
Alan informó de que, al realizar pruebas de estrés, KASAN detecta a veces un use-after-free durante el funcionamiento del canal de control (se elimina todo lo que no es relevante):
La última traza de pila es útil porque muestra que se está cancelando una solicitud; y, al observar tb_cfg_request_cancel(), lo que puede ocurrir es que tb_cfg_request_work() termine justo antes de que empiece tb_cfg_request_cancel() y, por ello, llame a schedule_work() encolando de nuevo el mismo trabajo para que se ejecute otra vez.
Leer descripción completaMostrar menos
Sin embargo, ya ha sido eliminado de request_queue y su contador de referencias se ha reducido, por lo que cuando tb_cfg_request_work() se dispara de nuevo accederá a memoria que ya ha sido liberada.
Para corregirlo, primero nos aseguramos de que una solicitud cancelada no se entregue desde tb_cfg_request_find() ni se programe para ejecutarse. Después, en lugar de confiar en que el worker realice la limpieza, la haremos en tb_cfg_request_cancel() una vez que el trabajo se haya cancelado antes de ejecutarse. Hacemos que tb_cfg_request_dequeue() libere la solicitud solo si realmente se ha eliminado de la cola.
Detalles técnicos trazas, registros y código del informe original
BUG: KASAN: slab-use-after-free in tb_cfg_request_sync+0x240/0x250 [thunderbolt] Read of size 24 at addr ffff88811067f290 by task kworker/u40:2/1760 <TASK> tb_cfg_request_sync+0x240/0x250 [thunderbolt] tb_cfg_read_raw+0x367/0x510 [thunderbolt] tb_cfg_read+0xec/0x240 [thunderbolt] tb_port_get_link_generation+0x258/0x420 [thunderbolt] tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt] tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt] tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt] tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt] tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt] process_one_work+0x675/0x1230 worker_thread+0x5e6/0xf70 kthread+0x365/0x470 ret_from_fork+0x54d/0x710 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 1760: __kmalloc_cache_noprof+0x1ee/0x550 tb_cfg_read_raw+0x1d3/0x510 [thunderbolt] tb_cfg_read+0xec/0x240 [thunderbolt] tb_port_get_link_generation+0x258/0x420 [thunderbolt] tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt] tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt] tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt] tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt] tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt] process_one_work+0x675/0x1230 worker_thread+0x5e6/0xf70 kthread+0x365/0x470 ret_from_fork+0x54d/0x710 ret_from_fork_asm+0x1a/0x30 Freed by task 926: kfree+0x18f/0x4a0 tb_cfg_request_put+0xb7/0xe0 [thunderbolt] tb_cfg_request_work+0x82/0x120 [thunderbolt] process_one_work+0x675/0x1230 worker_thread+0x5e6/0xf70 kthread+0x365/0x470 ret_from_fork+0x54d/0x710 ret_from_fork_asm+0x1a/0x30 Second to last potentially related work creation: __queue_work+0x575/0xd00 queue_work_on+0x77/0x80 tb_cfg_request_cancel+0xc7/0x260 [thunderbolt] tb_cfg_request_sync+0x1f6/0x250 [thunderbolt] tb_cfg_read_raw+0x367/0x510 [thunderbolt] tb_cfg_read+0xec/0x240 [thunderbolt] tb_port_get_link_generation+0x258/0x420 [thunderbolt] tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt] tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt] tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt] tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt] tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt] process_one_work+0x675/0x1230 worker_thread+0x5e6/0xf70 kthread+0x365/0x470 ret_from_fork+0x54d/0x710 ret_from_fork_asm+0x1a/0x30
Traducción automática del texto original de NVD (en inglés).
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
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
- 20/10/2026
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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
Mostrar las 4 referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98694",
"cveTags": [],
"metrics": {},
"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": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"lessThan": "71b3c517e02af2c46ad58d4b3706b7c3cb24936d",
"versionType": "git"
},
{
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"lessThan": "f18faa3d3b810d60a3005ae1b1d1866faa67d343",
"versionType": "git"
},
{
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"lessThan": "08287212b622039212c972806f896f078dfd28e2",
"versionType": "git"
},
{
"status": "affected",
"version": "d7f781bfdbf4eb7c5706c9974b8bf6d3c82e69c1",
"lessThan": "a02188ddc24b7872f0c5e0c5873f827318717803",
"versionType": "git"
}
],
"programFiles": [
"drivers/thunderbolt/ctl.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.13"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.13",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/thunderbolt/ctl.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:22.830",
"references": [
{
"url": "https://git.kernel.org/stable/c/08287212b622039212c972806f896f078dfd28e2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/71b3c517e02af2c46ad58d4b3706b7c3cb24936d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a02188ddc24b7872f0c5e0c5873f827318717803",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f18faa3d3b810d60a3005ae1b1d1866faa67d343",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: Fix KASAN reported use-after-free when request is canceled\n\nAlan reported that when doing stress testing sometimes KASAN notices\nuse-after-free during control channel operation (stripped down keeping\nthe relevant parts):\n\n BUG: KASAN: slab-use-after-free in tb_cfg_request_sync+0x240/0x250 [thunderbolt]\n Read of size 24 at addr ffff88811067f290 by task kworker/u40:2/1760\n <TASK>\n tb_cfg_request_sync+0x240/0x250 [thunderbolt]\n tb_cfg_read_raw+0x367/0x510 [thunderbolt]\n tb_cfg_read+0xec/0x240 [thunderbolt]\n tb_port_get_link_generation+0x258/0x420 [thunderbolt]\n tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]\n tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]\n tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]\n tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]\n tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\n Allocated by task 1760:\n __kmalloc_cache_noprof+0x1ee/0x550\n tb_cfg_read_raw+0x1d3/0x510 [thunderbolt]\n tb_cfg_read+0xec/0x240 [thunderbolt]\n tb_port_get_link_generation+0x258/0x420 [thunderbolt]\n tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]\n tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]\n tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]\n tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]\n tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n\n Freed by task 926:\n kfree+0x18f/0x4a0\n tb_cfg_request_put+0xb7/0xe0 [thunderbolt]\n tb_cfg_request_work+0x82/0x120 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n\n Second to last potentially related work creation:\n __queue_work+0x575/0xd00\n queue_work_on+0x77/0x80\n tb_cfg_request_cancel+0xc7/0x260 [thunderbolt]\n tb_cfg_request_sync+0x1f6/0x250 [thunderbolt]\n tb_cfg_read_raw+0x367/0x510 [thunderbolt]\n tb_cfg_read+0xec/0x240 [thunderbolt]\n tb_port_get_link_generation+0x258/0x420 [thunderbolt]\n tb_usb3_consumed_bandwidth+0x1c1/0x2c0 [thunderbolt]\n tb_tunnel_consumed_bandwidth+0xfd/0x910 [thunderbolt]\n tb_available_bandwidth+0x5f2/0xeb0 [thunderbolt]\n tb_recalc_estimated_bandwidth+0x2a0/0x1bc0 [thunderbolt]\n tb_handle_dp_bandwidth_request+0x1897/0x5e20 [thunderbolt]\n process_one_work+0x675/0x1230\n worker_thread+0x5e6/0xf70\n kthread+0x365/0x470\n ret_from_fork+0x54d/0x710\n ret_from_fork_asm+0x1a/0x30\n\nThe last stack trace is helpful because it shows that we are cancelling\na request and looking at tb_cfg_request_cancel() what might happen is\nthat tb_cfg_request_work() completes right before tb_cfg_request_cancel()\nstarts and because of this it will call schedule_work() queueing the\nsame work to run again. However, it is already removed from the\nrequest_queue and reference count is dropped so when\ntb_cfg_request_work() triggers again it will access memory that is\nalready released.\n\nFix this so that we first make sure a cancelled request is not handed\naway from tb_cfg_request_find() or scheduled to run. Then instead of\nrelying on the worker to clean up the request we will do it in\ntb_cfg_request_cancel() after the work is canceled from running. Make\ntb_cfg_request_dequeue() release the request only if it was actually\nremoved from the queue."
}
],
"lastModified": "2026-10-19T10:19:33.730",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}