[PATCH 4.14 154/218] serial: sh-sci: Dont allow CS5-6

[Greg Kroah-Hartman]

From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

[ Upstream commit 9b87162de8be26bf3156460b37deee6399fd0fcb ]

Only CS7 and CS8 seem supported but CSIZE is not sanitized from
CS5 or CS6 to CS8.

Set CSIZE correctly so that userspace knows the effective value.
Incorrect CSIZE also results in miscalculation of the frame bits in
tty_get_char_size() or in its predecessor where the roughly the same
code is directly within uart_update_timeout().

Fixes: 1da177e4c3f4 (Linux-2.6.12-rc2)
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220519081808.3776-6-ilpo.jarvinen@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/serial/sh-sci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 21f81dc08139..f7dd843a3eff 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -2267,8 +2267,12 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned long max_freq = 0;
 	int best_clk = -1;
 
-	if ((termios->c_cflag & CSIZE) == CS7)
+	if ((termios->c_cflag & CSIZE) == CS7) {
 		smr_val |= SCSMR_CHR;
+	} else {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+	}
 	if (termios->c_cflag & PARENB)
 		smr_val |= SCSMR_PE;
 	if (termios->c_cflag & PARODD)
-- 
2.35.1