[PATCH AUTOSEL 5.15 44/47] hwmon: (w83627ehf) Fix underflows seen when writing limit attributes

Sasha Levin
2024-08-01T00:35:32Z

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit 5c1de37969b7bc0abcb20b86e91e70caebbd4f89 ]

DIV_ROUND_CLOSEST() after kstrtol() results in an underflow if a large
negative number such as -9223372036854775808 is provided by the user.
Fix it by reordering clamp_val() and DIV_ROUND_CLOSEST() operations.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/w83627ehf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
index 705a59663d42c..b6bae04d656ed 100644
--- a/drivers/hwmon/w83627ehf.c
+++ b/drivers/hwmon/w83627ehf.c
@@ -895,7 +895,7 @@ store_target_temp(struct device *dev, struct device_attribute *attr,
if (err < 0)
return err;

- val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, 127);
+ val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 127000), 1000);

mutex_lock(&data->update_lock);
data->target_temp[nr] = val;
@@ -920,7 +920,7 @@ store_tolerance(struct device *dev, struct device_attribute *attr,
return err;

/* Limit the temp to 0C - 15C */
- val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, 15);
+ val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 15000), 1000);

mutex_lock(&data->update_lock);
reg = w83627ehf_read_value(data, W83627EHF_REG_TOLERANCE[nr]);
--
2.43.0