GHSA-X3FW-JWR8-PPM9
Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-19 18:32In 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.
{
"affected": [],
"aliases": [
"CVE-2026-68363"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T13:20:28Z",
"severity": null
},
"details": "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": "GHSA-x3fw-jwr8-ppm9",
"modified": "2026-08-19T18:32:17Z",
"published": "2026-08-10T15:33:48Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68363"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/063497cc9f320ab71a7a937c3bc0a23e630aefe2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/10b0ce629123a3737b4eda50188f73bb7be7b68b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/47ed81aaa7f94d9808f4719e78a760c2ec1e6c86"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/48a69cedde7388294e4ea6fd804156cd62bc04fc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/48de0c6952192b0771fca468df4364d11ec74ad9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7c9046d92c4b9789c9d9d775e4fd5f34be64cb0a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7f184ca38a90889f3f6665ff96748b95da39dbee"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dad9f96945d77ecd4708f730c06ef54dcd8cc057"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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Nomenclature
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