CVE-2026-97977

Summary

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.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/472d005622525b7be155cac99dde2252b0163bd1
• https://git.kernel.org/stable/c/93b59937bda3fffc6386c79f5544a39bc680c8e8
• https://git.kernel.org/stable/c/fa391adb9c755515a89993634745e9079e5ef37c
• https://git.kernel.org/stable/c/1c12c3117639e78940959d956519c758c57d0849

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