Skip to main content
VulnerabilityPublished Updated

CVE-2026-80947: Linux kernel · wifi: rtl8xxxu: fix use-after-free from rx_urb_wq on stop

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in 972ab8b9c08f3eb3fa535082de2950dd93604dfd : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 972ab8b9c08f3eb3fa535082de2950dd93604dfd, 800d2b490a9af1e7132a3564c2ad5a81292e5b40, 620acb1e8037b73a457dc8ef20fc23fc7adcb405 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 972ab8b9c08f3eb3fa535082de2950dd93604dfd
Fixed in
  • 972ab8b9c08f3eb3fa535082de2950dd93604dfd
LinuxLinuxAffected
  • ≥ 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 800d2b490a9af1e7132a3564c2ad5a81292e5b40
Fixed in
  • 800d2b490a9af1e7132a3564c2ad5a81292e5b40
LinuxLinuxAffected
  • ≥ 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 620acb1e8037b73a457dc8ef20fc23fc7adcb405
Fixed in
  • 620acb1e8037b73a457dc8ef20fc23fc7adcb405
LinuxLinuxAffected
  • ≥ 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 17d5ae58973122eea7625a87cd3d80a8beb23b47
Fixed in
  • 17d5ae58973122eea7625a87cd3d80a8beb23b47
LinuxLinuxAffected
  • ≥ 26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa, < 6c080026ecc17eecb103f8927c64ea73a74bb818
Fixed in
  • 6c080026ecc17eecb103f8927c64ea73a74bb818
LinuxLinuxAffected
  • =4.4
Fixed in–

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.

References

Community reviews

Loading reviews…