CVE-2026-80947
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtl8xxxu: fix use-after-free from rx_urb_wq on stop
rtl8xxxu arms rx_urb_wq from the RX completion path: rtl8xxxu_rx_complete() hands the URB to rtl8xxxu_queue_rx_urb(), which queues it on rx_urb_pending_list and, once the list grows past RTL8XXXU_RX_URB_PENDING_WATER, schedules rx_urb_wq. The worker rtl8xxxu_rx_urb_work() drains rx_urb_pending_list, recovers priv through container_of, and resubmits each URB through rtl8xxxu_submit_rx_urb(), which anchors it on rx_anchor and dereferences priv->udev.
rtl8xxxu_stop() cancels the sibling work items (c2hcmd_work, ra_watchdog, update_beacon_work) but never cancels rx_urb_wq, so a worker armed during the last burst of RX traffic can run rtl8xxxu_rx_urb_work() after rtl8xxxu_disconnect() has called ieee80211_free_hw(), which frees priv, producing a use-after-free.
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The window opens under active RX traffic (pending count above the watermark) followed by a disconnect.
There are two teardown races to close:
After priv->shutdown is set under rx_urb_lock, completions can no longer queue rx_urb_wq. cancel_work_sync() then drains the last queued or running worker, and the following usb_kill_anchored_urbs() kills the URBs it may have submitted.
rtl8xxxu_disconnect() is covered because ieee80211_unregister_hw() guarantees .stop() runs for a live interface before ieee80211_free_hw() frees priv. The probe error path needs no cancel: rx_urb_wq is INIT_WORK()'d there but cannot have been scheduled, since no URB is submitted before ieee80211_register_hw() succeeds.
This bug was found by static analysis.
Detalles técnicos trazas, registros y código del informe original
* rtl8xxxu_queue_rx_urb() decided whether to enqueue under rx_urb_lock
but called schedule_work() after dropping the lock. A completion
that observed shutdown == false and released the lock could then call
schedule_work() after rtl8xxxu_stop() had set shutdown and
cancel_work_sync() had already returned, arming the worker to run
after the teardown. Move schedule_work() under the same !shutdown
branch so the arming decision is atomic with the shutdown check.
* rtl8xxxu_rx_urb_work() anchors every URB it drained back onto
rx_anchor through rtl8xxxu_submit_rx_urb(). A worker still running
when usb_kill_anchored_urbs(&priv->rx_anchor) returned would submit a
URB that escaped the kill. In rtl8xxxu_stop(), call
cancel_work_sync(&priv->rx_urb_wq) before the kill so the worker is
drained first.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: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
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.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation75 % - Impacto principal
T1059Command and Scripting Interpreterexecution65 %
Vulnerabilidad de use-after-free (CWE-416) en controlador WiFi de kernel Linux con acceso local (AV:L) y privilegios limitados (PR:L). Permite ejecución de código arbitrario en contexto del kernel tras escalada de privilegios.
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
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-80947",
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"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
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"programFiles": [
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"published": "2026-09-11T20:19:00.303",
"references": [
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"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: rtl8xxxu: fix use-after-free from rx_urb_wq on stop\n\nrtl8xxxu arms rx_urb_wq from the RX completion path:\nrtl8xxxu_rx_complete() hands the URB to rtl8xxxu_queue_rx_urb(), which\nqueues it on rx_urb_pending_list and, once the list grows past\nRTL8XXXU_RX_URB_PENDING_WATER, schedules rx_urb_wq. The worker\nrtl8xxxu_rx_urb_work() drains rx_urb_pending_list, recovers priv through\ncontainer_of, and resubmits each URB through rtl8xxxu_submit_rx_urb(),\nwhich anchors it on rx_anchor and dereferences priv->udev.\n\nrtl8xxxu_stop() cancels the sibling work items (c2hcmd_work, ra_watchdog,\nupdate_beacon_work) but never cancels rx_urb_wq, so a worker armed during\nthe last burst of RX traffic can run rtl8xxxu_rx_urb_work() after\nrtl8xxxu_disconnect() has called ieee80211_free_hw(), which frees priv,\nproducing a use-after-free. The window opens under active RX traffic\n(pending count above the watermark) followed by a disconnect.\n\nThere are two teardown races to close:\n\n * rtl8xxxu_queue_rx_urb() decided whether to enqueue under rx_urb_lock\n but called schedule_work() after dropping the lock. A completion\n that observed shutdown == false and released the lock could then call\n schedule_work() after rtl8xxxu_stop() had set shutdown and\n cancel_work_sync() had already returned, arming the worker to run\n after the teardown. Move schedule_work() under the same !shutdown\n branch so the arming decision is atomic with the shutdown check.\n\n * rtl8xxxu_rx_urb_work() anchors every URB it drained back onto\n rx_anchor through rtl8xxxu_submit_rx_urb(). A worker still running\n when usb_kill_anchored_urbs(&priv->rx_anchor) returned would submit a\n URB that escaped the kill. In rtl8xxxu_stop(), call\n cancel_work_sync(&priv->rx_urb_wq) before the kill so the worker is\n drained first.\n\nAfter priv->shutdown is set under rx_urb_lock, completions can no longer\nqueue rx_urb_wq. cancel_work_sync() then drains the last queued or running\nworker, and the following usb_kill_anchored_urbs() kills the URBs it may\nhave submitted.\n\nrtl8xxxu_disconnect() is covered because ieee80211_unregister_hw()\nguarantees .stop() runs for a live interface before ieee80211_free_hw()\nfrees priv. The probe error path needs no cancel: rx_urb_wq is\nINIT_WORK()'d there but cannot have been scheduled, since no URB is\nsubmitted before ieee80211_register_hw() succeeds.\n\nThis bug was found by static analysis."
}
],
"lastModified": "2026-09-13T07:17:01.960",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}