nci_close_device() flushes rx_wq and tx_wq while holding req_lock.
This causes a circular locking dependency because nci_rx_work()
running on rx_wq can end up taking req_lock too:
nci_rx_work -> nci_rx_data_packet -> nci_data_exchange_complete
-> __sk_destruct -> rawsock_destruct -> nfc_deactivate_target
-> nci_deactivate_target -> nci_request -> mutex_lock(&ndev->req_lock)
Move the flush of rx_wq after req_lock has been released.
This should safe (I think) because NCI_UP has already been cleared
and the transport is closed, so the work will see it and return
-ENETDOWN.
NIPA has been hitting this running the nci selftest with a debug
kernel on roughly 4% of the runs.
Fixes: 6a2968aaf5 ("NFC: basic NCI protocol implementation")
Reviewed-by: Ian Ray <ian.ray@gehealthcare.com>
Link: https://patch.msgid.link/20260317193334.988609-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
4527025d44