CVE-2026-98109 — linux / linux_kernel
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix race condition during device registration
In hci_register_dev(), the power_on work item is queued to hdev->req_workqueue before initializing hdev->adv_monitors_idr and registering the MSFT extension via msft_register(). For devices marked with quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on the device. When the power_on work item runs concurrently on another CPU, hci_power_on() detects that the device is unconfigured and immediately invokes hci_dev_do_close(), which calls msft_do_close().
Concurrently, msft_register() allocates the msft structure and exposes it to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If msft_do_close() executes while hdev->msft_data is already assigned but the mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates on an uninitialized mutex, triggering a DEBUG_LOCKS warning:
DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline] WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821 ... Call Trace: <TASK> msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693 hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0x92d/0xe10 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK>
Fix this by moving the queue_work() call in hci_register_dev() to after idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device structures and extensions are fully initialized before asynchronous tasks can access them. Additionally, assign hdev->msft_data in msft_register() only after mutex_init(&msft->filter_lock) has completed.
| Software | Affected versions |
|---|---|
| linux / linux_kernel | >= 6.4.16, < 6.5 |
| linux / linux_kernel | >= 6.5.3, < 6.12.111 |
| linux / linux_kernel | >= 6.13, < 6.18.53 |
| linux / linux_kernel | >= 6.19, < 7.2.7 |
| linux / linux_kernel | = 7.3-rc1 |
- https://git.kernel.org/stable/c/57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18
- https://git.kernel.org/stable/c/593e64f64a20b25e4042c3ee863119eb7f991785
- https://git.kernel.org/stable/c/a11ebe8dc0333fb870bbbb656b34690e87ee3f98
- https://git.kernel.org/stable/c/b1faf348c29e6f8302ec7769cbf1c1ef05be014f
- https://git.kernel.org/stable/c/d427b1c71d9798083e954d3c13469dc0a2305868
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