From: Guenter Roeck <linux@roeck-us.net>
Date: Tue, 12 Jun 2018 22:19:35 +0000 (-0700)
Subject: hwmon: (nct6775) Fix loop limit
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4dff89e722d5186e9531a534f1000fee41798176;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

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 <pmenzel+linux-hwmon@molgen.mpg.de>
Cc: Paul Menzel <pmenzel+linux-hwmon@molgen.mpg.de>
Tested-by: Paul Menzel <pmenzel+linux-hwmon@molgen.mpg.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/hwmon/nct6775.c b/drivers/hwmon/nct6775.c
index f5f3f8cf57ea..5f87764d7015 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 <mask>
 	 * 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])