CVE-2026-97977

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btusb: Fix UAF of btusb_data by rx_work

btusb_close() and btusb_flush() cancel data->rx_work with the

asynchronous cancel_delayed_work(), so if btusb_rx_work() is already

running on another CPU it keeps running after the cancel returns.

btusb_disconnect() calls hci_unregister_dev(), which invokes

btusb_close(), and then frees the btusb_data. A still running

btusb_rx_work() then dereferences the freed data:

while ((skb = skb_dequeue(&data->acl_q)))

data->recv_acl(data->hdev, skb);

Use cancel_delayed_work_sync() instead. In btusb_close() the cancel also

has to happen after btusb_stop_traffic(), otherwise an URB completion

racing with the cancel can requeue the work right after it has been

waited for.