From 4dff89e722d5186e9531a534f1000fee41798176 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 12 Jun 2018 15:19:35 -0700 Subject: [PATCH] hwmon: (nct6775) Fix loop limit [ Upstream commit 91bb8f45f73f19a0150c233c0f11cdeb6d71d1e9 ] 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 Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/nct6775.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c index f5f3f8c..5f87764 100644 --- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -4107,7 +4107,7 @@ 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]) -- 2.7.4