From df8185cd25af0f25e73dadbf098673c80ea48816 Mon Sep 17 00:00:00 2001 From: Daniel Starke Date: Thu, 14 Apr 2022 02:42:12 -0700 Subject: [PATCH] tty: n_gsm: fix malformed counter for out of frame data commit a24b4b2f660b7ddf3f484b37600bba382cb28a9d 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: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke Link: https://lore.kernel.org/r/20220414094225.4527-7-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 4ce18b42c37ac..2e3da8a4697e4 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2044,7 +2044,8 @@ static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) } /* Any partial frame was a runt so go back to start */ if (gsm->state != GSM_START) { - gsm->malformed++; + if (gsm->state != GSM_SEARCH) + gsm->malformed++; gsm->state = GSM_START; } /* A SOF in GSM_START means we are still reading idling or