Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9fe2069a authored by Guenter Roeck's avatar Guenter Roeck Committed by Greg Kroah-Hartman
Browse files

hwmon: (max6697) Fix underflow when writing limit attributes 



[ Upstream commit cbf7467828cd4ec7ceac7a8b5b5ddb2f69f07b0e ]

Using DIV_ROUND_CLOSEST() on an unbound value can result in underflows.
Indeed, module test scripts report:

temp1_max: Suspected underflow: [min=0, read 255000, written -9223372036854775808]
temp1_crit: Suspected underflow: [min=0, read 255000, written -9223372036854775808]

Fix by introducing an extra set of clamping.

Fixes: 5372d2d7 ("hwmon: Driver for Maxim MAX6697 and compatibles")
Reviewed-by: default avatarTzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 47f4d260

drivers/hwmon/max6697.c

+1 −0
Original line number Diff line number Diff line
@@ -305,6 +305,7 @@ static ssize_t temp_store(struct device *dev, 
		return ret;



	mutex_lock(&data->update_lock);

	temp = clamp_val(temp, -1000000, 1000000);	/* prevent underflow */

	temp = DIV_ROUND_CLOSEST(temp, 1000) + data->temp_offset;

	temp = clamp_val(temp, 0, data->type == max6581 ? 255 : 127);

	data->temp[nr][index] = temp;