{"id":"CVE-2026-68363","summary":"wifi: ath9k: hif_usb: don't dereference hif_dev after re-arming firmware request","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath9k: hif_usb: don't 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(&hif_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(&hif_dev-\u003efw_done). That\nreleases the wait_for_completion(&hif_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.","modified":"2026-08-21T03:30:27.759338172Z","published":"2026-08-10T12:03:40.355Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68363.json","cna_assigner":"Linux"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68363.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68363"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e904cf6fe23022cde4e0ea9d41601411a315a3dc"},{"fixed":"47ed81aaa7f94d9808f4719e78a760c2ec1e6c86"},{"fixed":"48de0c6952192b0771fca468df4364d11ec74ad9"},{"fixed":"063497cc9f320ab71a7a937c3bc0a23e630aefe2"},{"fixed":"7f184ca38a90889f3f6665ff96748b95da39dbee"},{"fixed":"10b0ce629123a3737b4eda50188f73bb7be7b68b"},{"fixed":"48a69cedde7388294e4ea6fd804156cd62bc04fc"},{"fixed":"7c9046d92c4b9789c9d9d775e4fd5f34be64cb0a"},{"fixed":"dad9f96945d77ecd4708f730c06ef54dcd8cc057"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68363.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.4.0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68363.json"}}],"schema_version":"1.9.0"}