HCI_UART_SENDING bit in tx_state means write_work is pending and blocks
queueing it again. Currently this bit is not cleared when canceling the
work in hci_uart_close(), which blocks future writes when device is
reopened later if write_work was pending.
Fix by clearing HCI_UART_SENDING when canceling the work.
Also make clearing of tx_skb safe by using disable_work_sync +
enable_work instead of just cancel_work_sync. hci_uart_flush() purges
the proto tx queue so we can cancel the pending write_work there,
instead of doing it just in hci_uart_close(). Re-enable and possibly
requeue the work after queue flush.
Fixes: c1bb9336ae ("Bluetooth: hci_uart: fix UAFs and race conditions in close and init paths")
Link: https://lore.kernel.org/linux-bluetooth/07e0a28650773abec711ee492fdb1bf5d21a6c98.camel@iki.fi/
Cc: stable@vger.kernel.org
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
1b0d946d6f