FKIE_CVE-2026-68363

Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-19 17:20
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k: hif_usb: don't dereference hif_dev after re-arming firmware request ath9k_hif_request_firmware() re-arms an asynchronous firmware load via request_firmware_nowait(), passing hif_dev as the completion context, and then still dereferences hif_dev: dev_info(&hif_dev->udev->dev, "ath9k_htc: Firmware %s requested\n", hif_dev->fw_name); The re-armed callback ath9k_hif_usb_firmware_cb() runs on the "events" workqueue and, when the firmware is missing, walks the retry chain into ath9k_hif_usb_firmware_fail() -> complete_all(&hif_dev->fw_done). That releases the wait_for_completion(&hif_dev->fw_done) in a concurrent ath9k_hif_usb_disconnect(), which then kfree()s hif_dev. The trailing dev_info() in the frame that re-armed the request can therefore read freed memory (hif_dev->udev, the first field of struct hif_device_usb): BUG: KASAN: slab-use-after-free in ath9k_hif_request_firmware Read of size 8 ... by task kworker/... ath9k_hif_request_firmware ath9k_hif_usb_firmware_cb drivers/net/wireless/ath/ath9k/hif_usb.c:1247 request_firmware_work_func Allocated by ...: ath9k_hif_usb_probe drivers/net/wireless/ath/ath9k/hif_usb.c Freed by ...: ath9k_hif_usb_disconnect -> kfree drivers/net/wireless/ath/ath9k/hif_usb.c The fw_done barrier only makes disconnect wait for the firmware chain to *terminate*; it does not protect the outer ath9k_hif_request_firmware() frame that re-armed the request and keeps touching hif_dev afterwards. Drop the post-request dev_info(): it is the only use of hif_dev after the async request is armed, and it is purely informational (the dev_err() on the failure path runs only when request_firmware_nowait() did not arm a callback, so hif_dev is still alive there). This was first reported by syzbot as a single, non-reproduced crash that was later auto-obsoleted, and was independently rediscovered by the reFuzz fuzzer, which produced a C reproducer (USB-gadget connect/disconnect of an ath9k_htc device whose firmware download fails). The vulnerable code is unchanged and still present in v7.1-rc6, where the slab-use-after-free reproduces under KASAN once the (sub-microsecond) race window is widened.
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wireless/ath/ath9k/hif_usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "47ed81aaa7f94d9808f4719e78a760c2ec1e6c86",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "48de0c6952192b0771fca468df4364d11ec74ad9",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "063497cc9f320ab71a7a937c3bc0a23e630aefe2",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "7f184ca38a90889f3f6665ff96748b95da39dbee",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "10b0ce629123a3737b4eda50188f73bb7be7b68b",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "48a69cedde7388294e4ea6fd804156cd62bc04fc",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "7c9046d92c4b9789c9d9d775e4fd5f34be64cb0a",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            },
            {
              "lessThan": "dad9f96945d77ecd4708f730c06ef54dcd8cc057",
              "status": "affected",
              "version": "e904cf6fe23022cde4e0ea9d41601411a315a3dc",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wireless/ath/ath9k/hif_usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.4"
            },
            {
              "lessThan": "4.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath9k: hif_usb: don\u0027t dereference hif_dev after re-arming firmware request\n\nath9k_hif_request_firmware() re-arms an asynchronous firmware load via\nrequest_firmware_nowait(), passing hif_dev as the completion context, and\nthen still dereferences hif_dev:\n\n\tdev_info(\u0026hif_dev-\u003eudev-\u003edev, \"ath9k_htc: Firmware %s requested\\n\",\n\t\t hif_dev-\u003efw_name);\n\nThe re-armed callback ath9k_hif_usb_firmware_cb() runs on the \"events\"\nworkqueue and, when the firmware is missing, walks the retry chain into\nath9k_hif_usb_firmware_fail() -\u003e complete_all(\u0026hif_dev-\u003efw_done). That\nreleases the wait_for_completion(\u0026hif_dev-\u003efw_done) in a concurrent\nath9k_hif_usb_disconnect(), which then kfree()s hif_dev. The trailing\ndev_info() in the frame that re-armed the request can therefore read freed\nmemory (hif_dev-\u003eudev, the first field of struct hif_device_usb):\n\n  BUG: KASAN: slab-use-after-free in ath9k_hif_request_firmware\n  Read of size 8 ... by task kworker/...\n   ath9k_hif_request_firmware\n   ath9k_hif_usb_firmware_cb           drivers/net/wireless/ath/ath9k/hif_usb.c:1247\n   request_firmware_work_func\n  Allocated by ...:\n   ath9k_hif_usb_probe                 drivers/net/wireless/ath/ath9k/hif_usb.c\n  Freed by ...:\n   ath9k_hif_usb_disconnect -\u003e kfree   drivers/net/wireless/ath/ath9k/hif_usb.c\n\nThe fw_done barrier only makes disconnect wait for the firmware chain to\n*terminate*; it does not protect the outer ath9k_hif_request_firmware()\nframe that re-armed the request and keeps touching hif_dev afterwards.\n\nDrop the post-request dev_info(): it is the only use of hif_dev after the\nasync request is armed, and it is purely informational (the dev_err() on the\nfailure path runs only when request_firmware_nowait() did not arm a callback,\nso hif_dev is still alive there).\n\nThis was first reported by syzbot as a single, non-reproduced crash that was\nlater auto-obsoleted, and was independently rediscovered by the reFuzz fuzzer,\nwhich produced a C reproducer (USB-gadget connect/disconnect of an ath9k_htc\ndevice whose firmware download fails). The vulnerable code is unchanged and\nstill present in v7.1-rc6, where the slab-use-after-free reproduces under KASAN\nonce the (sub-microsecond) race window is widened."
    }
  ],
  "id": "CVE-2026-68363",
  "lastModified": "2026-08-19T17:20:45.943",
  "metrics": {},
  "published": "2026-08-10T13:20:28.870",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/063497cc9f320ab71a7a937c3bc0a23e630aefe2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/10b0ce629123a3737b4eda50188f73bb7be7b68b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/47ed81aaa7f94d9808f4719e78a760c2ec1e6c86"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/48a69cedde7388294e4ea6fd804156cd62bc04fc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/48de0c6952192b0771fca468df4364d11ec74ad9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7c9046d92c4b9789c9d9d775e4fd5f34be64cb0a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7f184ca38a90889f3f6665ff96748b95da39dbee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dad9f96945d77ecd4708f730c06ef54dcd8cc057"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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