tree 77823a2764ec286cb4a43681451c8ebf08494aba
parent 5b3417b60e43ff03a96f533ee374da13f17b4840
author Daniel Starke <daniel.starke@siemens.com> 1649929335 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1652350496 +0200

tty: n_gsm: fix missing explicit ldisc flush

commit 17eac652028501df7ea296b1d9b9c134db262b7d upstream.

In gsm_cleanup_mux() the muxer is closed down and all queues are removed.
However, removing the queues is done without explicit control of the
underlying buffers. Flush those before freeing up our queues to ensure
that all outgoing queues are cleared consistently. Otherwise, a new mux
connection establishment attempt may time out while the underlying tty is
still busy sending out the remaining data from the previous connection.

Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220414094225.4527-10-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>