cec TransmitMsg UAF

In the Linux kernel, the following vulnerability has been resolved: media: cec: disable delayed work before freeing an interrupted transmit cec_transmit_msg_fh() drops adap->lock to wait for a blocking transmit in wait_for_completion_killable(). If that wait is interrupted by a signal, cancel_delayed_work_sync() can run before the CEC kthread arms the reply timeout via schedule_delayed_work(&data->work) in cec_transmit_done_ts(). The work is then armed after the cancel, and the data is freed with its delayed_work still pending: ODEBUG: free active (active state 0) object: ... hint: cec_wait_timeout Use disable_delayed_work_sync(): it cancels the work and disables it, so the later schedule_delayed_work() becomes a no-op and the work cannot be re-armed. The data is freed right after, so it need not be re-enabled.