serial: txx9: Don't allow CS5-6

Only CS7 and CS8 are supported but CSIZE is not sanitized with
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@linux.intel.com>
Link: https://lore.kernel.org/r/20220519081808.3776-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index 2213e6b841d3da3df8c18850c35cb23ea238ed56..228e380db0804de1e83355c66113ed18a5411a9e 100644 (file)
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -618,6 +618,8 @@ serial_txx9_set_termios(struct uart_port *up, struct ktermios *termios,
        case CS6:       /* not supported */
        case CS8:
                cval |= TXX9_SILCR_UMODE_8BIT;
+               termios->c_cflag &= ~CSIZE;
+               termios->c_cflag |= CS8;
                break;
        }