[PATCH 2/7] USB: serial: ftdi_sio: Add missing baudrate validation

["Marek Behún" <kabel@kernel.org>]

From: Pali Rohár <pali@kernel.org>

More FTDI variants limit the minimal baudrate value. Add lower bound
checks.

Signed-off-by: Pali Rohár <pali@kernel.org>
Tested-by: Marek Behún <kabel@kernel.org>
---
 drivers/usb/serial/ftdi_sio.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index ea40f367e70c..717b97f4e094 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1330,7 +1330,7 @@ static u32 get_ftdi_divisor(struct tty_struct *tty,
 		}
 		break;
 	case FT8U232AM: /* 8U232AM chip */
-		if (baud <= 3000000) {
+		if (baud >= 183 && baud <= 3000000) {
 			div_value = ftdi_232am_baud_to_divisor(baud);
 		} else {
 			dev_dbg(dev, "%s - Baud rate too high!\n", __func__);
@@ -1343,7 +1343,7 @@ static u32 get_ftdi_divisor(struct tty_struct *tty,
 	case FT2232C: /* FT2232C chip */
 	case FT232RL: /* FT232RL chip */
 	case FTX:     /* FT-X series */
-		if (baud <= 3000000) {
+		if (baud >= 183 && baud <= 3000000) {
 			u16 product_id = le16_to_cpu(
 				port->serial->dev->descriptor.idProduct);
 			if (((product_id == FTDI_NDI_HUC_PID)		||
@@ -1367,7 +1367,7 @@ static u32 get_ftdi_divisor(struct tty_struct *tty,
 	case FT232H:  /* FT232H chip */
 		if ((baud <= 12000000) && (baud >= 1200)) {
 			div_value = ftdi_2232h_baud_to_divisor(baud);
-		} else if (baud < 1200) {
+		} else if (baud >= 183 && baud < 1200) {
 			div_value = ftdi_232bm_baud_to_divisor(baud);
 		} else {
 			dev_dbg(dev, "%s - Baud rate too high!\n", __func__);
-- 
2.35.1