CVE-2026-80947

Full vulnerability record from the local CVENow database.

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.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-11 20:19:00.303000

Last modified

2026-10-30 13:20:14.127000

View original CVE JSON

{
  "id": "CVE-2026-80947",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:00.303",
  "lastModified": "2026-10-30T13:20:14.127",
  "vulnStatus": "Received",
  "cveTags": [],
  "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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/wireless/realtek/rtl8xxxu/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "75e7e19e9218e3b895e652f04acf08113dc3aa00",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "da1678cca182567fd84618b689f4424f3f55f712",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "06e6bbb0abc2ae22e6e4d184250075e5c9e090d6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "17d5ae58973122eea7625a87cd3d80a8beb23b47",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "800d2b490a9af1e7132a3564c2ad5a81292e5b40",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "620acb1e8037b73a457dc8ef20fc23fc7adcb405",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "972ab8b9c08f3eb3fa535082de2950dd93604dfd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "26f1fad29ad973b0fb26a9ca3dcb2a73dde781aa",
              "lessThan": "6c080026ecc17eecb103f8927c64ea73a74bb818",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/wireless/realtek/rtl8xxxu/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.4",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.4",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.273",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.224",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.109",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/06e6bbb0abc2ae22e6e4d184250075e5c9e090d6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/17d5ae58973122eea7625a87cd3d80a8beb23b47",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
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}