From d7834d92251baade796812876e95555e2066fa9f Mon Sep 17 00:00:00 2001 From: Abdurrahman Hussain Date: Mon, 18 May 2026 17:52:25 -0700 Subject: [PATCH] hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR adm1266_gpio_get_multiple() iterates the PDIO portion of the caller-supplied mask using for_each_set_bit_from(gpio_nr, mask, ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) { ... } where ADM1266_PDIO_STATUS is the PMBus command code (0xE9, i.e. 233), not the number of PDIO pins. The intended upper bound is ADM1266_GPIO_NR + ADM1266_PDIO_NR = 25. gpiolib hands in a mask sized for gc.ngpio (= 25 bits on this chip), so the iteration walks find_next_bit() up to 242, reading up to 217 extra bits (a handful of unsigned-long words: four on 64-bit, seven on 32-bit) of whatever lives past the end of the mask in the caller's stack. Any incidental set bit in that range then drives a set_bit(gpio_nr, bits) call that writes past the end of the caller-supplied bits array too -- both out-of-bounds. Substitute ADM1266_PDIO_NR for the constant so the scan stops at the last real PDIO bit. Fixes: d98dfad35c38 ("hwmon: (pmbus/adm1266) Add support for GPIOs") Cc: stable@vger.kernel.org Signed-off-by: Abdurrahman Hussain Reviewed-by: Bartosz Golaszewski Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-1-e425e4f88139@nexthop.ai Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/adm1266.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c index 1fcd86ee96fe..4b2a8a765a4e 100644 --- a/drivers/hwmon/pmbus/adm1266.c +++ b/drivers/hwmon/pmbus/adm1266.c @@ -212,7 +212,7 @@ static int adm1266_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask status = read_buf[0] + (read_buf[1] << 8); *bits = 0; - for_each_set_bit_from(gpio_nr, mask, ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) { + for_each_set_bit_from(gpio_nr, mask, ADM1266_GPIO_NR + ADM1266_PDIO_NR) { if (test_bit(gpio_nr - ADM1266_GPIO_NR, &status)) set_bit(gpio_nr, bits); }