commit a24b4b2f66 upstream.
The gsm_mux field 'malformed' represents the number of malformed frames
received. However, gsm1_receive() also increases this counter for any out
of frame byte.
Fix this by ignoring out of frame data for the malformed counter.
Fixes: e1eaea46bb ("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/20220414094225.4527-7-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
a93d2d3189