From: Guenter Roeck Date: Tue, 12 Jun 2018 22:19:35 +0000 (-0700) Subject: hwmon: (nct6775) Fix loop limit X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=91bb8f45f73f19a0150c233c0f11cdeb6d71d1e9;p=linux.git hwmon: (nct6775) Fix loop limit Commit cc66b3038254 ("hwmon: (nct6775) Rework temperature source and label handling") changed a loop limit from "data->temp_label_num - 1" to "32", as part of moving from a string array to a bit mask. This results in the following error, reported by UBSAN. UBSAN: Undefined behaviour in drivers/hwmon/nct6775.c:4179:27 shift exponent 32 is too large for 32-bit type 'long unsigned int' Similar to the original loop, the limit has to be one less than the number of bits. Fixes: cc66b3038254 ("hwmon: (nct6775) Rework temperature source and label handling") Reported-by: Paul Menzel Cc: Paul Menzel Tested-by: Paul Menzel Signed-off-by: Guenter Roeck --- diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c index 155d4d1d1585a..f9d1349c32869 100644 --- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -4175,7 +4175,7 @@ static int nct6775_probe(struct platform_device *pdev) * The temperature is already monitored if the respective bit in * is set. */ - for (i = 0; i < 32; i++) { + for (i = 0; i < 31; i++) { if (!(data->temp_mask & BIT(i + 1))) continue; if (!reg_temp_alternate[i])