pinctrl: mediatek: fix global-out-of-bounds issue

When eint virtual eint number is greater than gpio number,
it maybe produce 'desc[eint_n]' size globle-out-of-bounds issue.

Signed-off-by: Guodong Liu <[email protected]>
Signed-off-by: Zhiyong Tao <[email protected]>
Reviewed-by: Chen-Yu Tsai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>

Author: Guodong Liu

drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c

@@ -285,8 +285,12 @@ static int mtk_xt_get_gpio_n(void *data, unsigned long eint_n,
 	desc = (const struct mtk_pin_desc *)hw->soc->pins;
 	*gpio_chip = &hw->chip;
 
-	/* Be greedy to guess first gpio_n is equal to eint_n */
-	if (desc[eint_n].eint.eint_n == eint_n)
+	/*
+	 * Be greedy to guess first gpio_n is equal to eint_n.
+	 * Only eint virtual eint number is greater than gpio number.
+	 */
+	if (hw->soc->npins > eint_n &&
+	    desc[eint_n].eint.eint_n == eint_n)
 		*gpio_n = eint_n;
 	else
 		*gpio_n = mtk_xt_find_eint_num(hw, eint_n);