CVE-2026-80947: Linux Vulnerability (CVSS 7.8)

Description

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. The window opens under active RX traffic (pending count above the watermark) followed by a disconnect. There are two teardown races to close: * 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. 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.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.20%

10.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 800d2b490a9af1e7132a3564c2ad5a81292e5b40; >= 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 620acb1e8037b73a457dc8ef20fc23fc7adcb405; >= 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 972ab8b9c08f3eb3fa535082de2950dd93604dfd; >= 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 6c080026ecc17eecb103f8927c64ea73a74bb818
Linux	Linux	4.4

References

Timeline

Published: Sep 11, 2026
Last Modified: Sep 13, 2026
Status: Received

Frequently Asked Questions

What is 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. The window opens under active RX traffic (pending count above the watermark) followed by a disconnect. There are two teardown races to close: * 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. 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.

How severe is CVE-2026-80947?

CVE-2026-80947 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.

How do I fix CVE-2026-80947?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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