From: Colin Ian King Date: Thu, 5 Nov 2020 11:50:19 +0000 (+0000) Subject: hwmon: (corsair-psu) fix unintentional sign extension issue X-Git-Tag: microblaze-v5.12~158^2~34 X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=90673f713fceaa50eef1bff0bcc8ee4e6fbc8953 hwmon: (corsair-psu) fix unintentional sign extension issue The shifting of the u8 integer data[3] by 24 bits to the left will be promoted to a 32 bit signed int and then sign-extended to a long. In the event that the top bit of data[3] is set then all then all the upper 32 bits of a 64 bit long end up as also being set because of the sign-extension. Fix this by casting data[3] to a long before the shift. Addresses-Coverity: ("Unintended sign extension") Fixes: ce15cd2cee8b ("hwmon: add Corsair PSU HID controller driver") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20201105115019.41735-1-colin.king@canonical.com Signed-off-by: Guenter Roeck --- diff --git a/drivers/hwmon/corsair-psu.c b/drivers/hwmon/corsair-psu.c index e92d0376e7ac..5d19a888231a 100644 --- a/drivers/hwmon/corsair-psu.c +++ b/drivers/hwmon/corsair-psu.c @@ -241,7 +241,7 @@ static int corsairpsu_get_value(struct corsairpsu_data *priv, u8 cmd, u8 rail, l * the LINEAR11 conversion are the watts values which are about 1200 for the strongest psu * supported (HX1200i) */ - tmp = (data[3] << 24) + (data[2] << 16) + (data[1] << 8) + data[0]; + tmp = ((long)data[3] << 24) + (data[2] << 16) + (data[1] << 8) + data[0]; switch (cmd) { case PSU_CMD_IN_VOLTS: case PSU_CMD_IN_AMPS: