This is a note to let you know that I've just added the patch titled serial: st-asc: Sanitize CSIZE and correct PARENB for CS7 to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-st-asc-sanitize-csize-and-correct-parenb-for-.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2ca8a4edb419ef51f97b4a5d0f88aba7a618871a Author: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Date: Thu May 19 11:18:06 2022 +0300 serial: st-asc: Sanitize CSIZE and correct PARENB for CS7 [ Upstream commit 52bb1cb7118564166b04d52387bd8403632f5190 ] Only CS7 and CS8 seem supported but CSIZE is not sanitized from CS5 or CS6 to CS8. In addition, ASC_CTL_MODE_7BIT_PAR suggests that CS7 has to have parity, thus add PARENB. Incorrect CSIZE 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: c4b058560762 (serial:st-asc: Add ST ASC driver.) Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220519081808.3776-8-ilpo.jarvinen@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c index e7048515a79c..97d36f870f64 100644 --- a/drivers/tty/serial/st-asc.c +++ b/drivers/tty/serial/st-asc.c @@ -535,10 +535,14 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios, /* set character length */ if ((cflag & CSIZE) == CS7) { ctrl_val |= ASC_CTL_MODE_7BIT_PAR; + cflag |= PARENB; } else { ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR : ASC_CTL_MODE_8BIT; + cflag &= ~CSIZE; + cflag |= CS8; } + termios->c_cflag = cflag; /* set stop bit */ ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;