{"id":"CVE-2026-98109","published":"2026-09-25T11:17:41.977","lastModified":"2026-09-25T11:17:41.977","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Fix race condition during device registration\n\nIn hci_register_dev(), the power_on work item is queued to\nhdev->req_workqueue before initializing hdev->adv_monitors_idr and\nregistering the MSFT extension via msft_register(). For devices marked with\nquirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on\nthe device. When the power_on work item runs concurrently on another CPU,\nhci_power_on() detects that the device is unconfigured and immediately\ninvokes hci_dev_do_close(), which calls msft_do_close().\n\nConcurrently, msft_register() allocates the msft structure and exposes it\nto hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If\nmsft_do_close() executes while hdev->msft_data is already assigned but the\nmutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates\non an uninitialized mutex, triggering a DEBUG_LOCKS warning:\n\nDEBUG_LOCKS_WARN_ON(lock->magic != lock)\nWARNING: kernel/locking/mutex.c:625 at __mutex_lock_common\nkernel/locking/mutex.c:625 [inline]\nWARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550\nkernel/locking/mutex.c:821\n...\nCall Trace:\n <TASK>\n msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693\n hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522\n hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]\n hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937\n process_one_work kernel/workqueue.c:3322 [inline]\n process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405\n worker_thread+0x92d/0xe10 kernel/workqueue.c:3486\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TASK>\n\nFix this by moving the queue_work() call in hci_register_dev() to after\nidr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device\nstructures and extensions are fully initialized before asynchronous tasks\ncan access them. Additionally, assign hdev->msft_data in msft_register()\nonly after mutex_init(&msft->filter_lock) has completed.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18","tags":[]},{"url":"https://git.kernel.org/stable/c/a11ebe8dc0333fb870bbbb656b34690e87ee3f98","tags":[]},{"url":"https://git.kernel.org/stable/c/b1faf348c29e6f8302ec7769cbf1c1ef05be014f","tags":[]},{"url":"https://git.kernel.org/stable/c/d427b1c71d9798083e954d3c13469dc0a2305868","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}