power: supply: gpio-charger: Fix set charge current limits

commit afc6e39 upstream.

Fix set charge current limits for devices which allow to set the lowest
charge current limit to be greater zero. If requested charge current limit
is below lowest limit, the index equals current_limit_map_size which leads
to accessing memory beyond allocated memory.

Fixes: be2919d ("power: supply: gpio-charger: add charge-current-limit feature")
Cc: stable@vger.kernel.org
Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
Link: https://lore.kernel.org/r/20241209-fix-charge-current-limit-v1-1-760d9b8f2af3@liebherr.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: DimitriFedrau

drivers/power/supply/gpio-charger.c

@@ -67,6 +67,14 @@ static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val)
 		if (gpio_charger->current_limit_map[i].limit_ua <= val)
 			break;
 	}
+
+	/*
+	 * If a valid charge current limit isn't found, default to smallest
+	 * current limitation for safety reasons.
+	 */
+	if (i >= gpio_charger->current_limit_map_size)
+		i = gpio_charger->current_limit_map_size - 1;
+
 	mapping = gpio_charger->current_limit_map[i];
 
 	for (i = 0; i < ndescs; i++) {