power: supply: max17042: avoid overflow when determining health

If vmax has the default value of INT_MAX (e.g. because not specified in
DT), battery health is reported as over-voltage. This is because adding
any value to vmax (the vmax tolerance in this case) causes it to wrap
around, making it negative and smaller than the measured battery
voltage.

Avoid that by using size_add().

Fixes: edd4ab055931 ("power: max17042_battery: add HEALTH and TEMP_* properties support")
Cc: stable@vger.kernel.org
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260302-max77759-fg-v3-6-3c5f01dbda23@linaro.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index b9277f81a25d0ced162326c4bf7c5167d1eb98bd..39091fb317119d478e556084166d7a1da8d4efe7 100644 (file)
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -201,7 +201,7 @@ static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
                goto out;
        }
 
-       if (vbatt > chip->pdata->vmax + MAX17042_VMAX_TOLERANCE) {
+       if (vbatt > size_add(chip->pdata->vmax, MAX17042_VMAX_TOLERANCE)) {
                *health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
                goto out;
        }