From: Pali Rohár <pali@xxxxxxxxxx> Divisor in the register is a 17-bit wide number. Therefore we need to clamp it on overflow. Signed-off-by: Pali Rohár <pali@xxxxxxxxxx> Tested-by: Marek Behún <kabel@xxxxxxxxxx> --- drivers/usb/serial/ftdi_sio.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index b440d338a895..ea40f367e70c 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1157,6 +1157,8 @@ static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base) int divisor3 = DIV_ROUND_CLOSEST(base, 2 * baud); if ((divisor3 & 0x7) == 7) divisor3++; /* round x.7/8 up to x+1 */ + if (divisor3 > GENMASK(16, 0)) + divisor3 = GENMASK(16, 0); divisor = divisor3 >> 3; divisor3 &= 0x7; if (divisor3 == 1) @@ -1181,6 +1183,8 @@ static u32 ftdi_232bm_baud_base_to_divisor(int baud, int base) u32 divisor; /* divisor shifted 3 bits to the left */ int divisor3 = DIV_ROUND_CLOSEST(base, 2 * baud); + if (divisor3 > GENMASK(16, 0)) + divisor3 = GENMASK(16, 0); divisor = divisor3 >> 3; divisor |= (u32)divfrac[divisor3 & 0x7] << 14; /* Deal with special cases for highest baud rates. */ @@ -1204,6 +1208,8 @@ static u32 ftdi_2232h_baud_base_to_divisor(int baud, int base) /* hi-speed baud rate is 10-bit sampling instead of 16-bit */ divisor3 = DIV_ROUND_CLOSEST(8 * base, 10 * baud); + if (divisor3 > GENMASK(16, 0)) + divisor3 = GENMASK(16, 0); divisor = divisor3 >> 3; divisor |= (u32)divfrac[divisor3 & 0x7] << 14; -- 2.35.1
