From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bh-25.webhostbox.net ([208.91.199.152]:38885 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936058AbeFMPKk (ORCPT ); Wed, 13 Jun 2018 11:10:40 -0400 From: Guenter Roeck To: Hardware Monitoring Cc: Jean Delvare , Guenter Roeck , Paul Menzel Subject: [PATCH] hwmon: (nct6775) Fix loop limit Date: Wed, 13 Jun 2018 08:10:36 -0700 Message-Id: <1528902636-9810-1-git-send-email-linux@roeck-us.net> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org 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 Signed-off-by: Guenter Roeck --- 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 aebce560bfaf..b14eb73bc3c9 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]) -- 2.7.4