6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> commit 9d846b1aebbe488f245f1aa463802ff9c34cc078 upstream. As per the API contract - gpio_chip::get_direction() may fail and return a negative error number. However, we treat it as if it always returned 0 or 1. Check the return value of the callback and propagate the error number up the stack. Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Link: https://lore.kernel.org/r/20250210-gpio-sanitize-retvals-v1-1-12ea88506cb2@xxxxxxxxxx Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpio/gpiolib.c | 44 +++++++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 15 deletions(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1057,8 +1057,11 @@ int gpiochip_add_data_with_key(struct gp desc->gdev = gdev; if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) { - assign_bit(FLAG_IS_OUT, - &desc->flags, !gc->get_direction(gc, desc_index)); + ret = gc->get_direction(gc, desc_index); + if (ret < 0) + goto err_cleanup_desc_srcu; + + assign_bit(FLAG_IS_OUT, &desc->flags, !ret); } else { assign_bit(FLAG_IS_OUT, &desc->flags, !gc->direction_input); @@ -2728,13 +2731,18 @@ int gpiod_direction_input_nonotify(struc if (guard.gc->direction_input) { ret = guard.gc->direction_input(guard.gc, gpio_chip_hwgpio(desc)); - } else if (guard.gc->get_direction && - (guard.gc->get_direction(guard.gc, - gpio_chip_hwgpio(desc)) != 1)) { - gpiod_warn(desc, - "%s: missing direction_input() operation and line is output\n", - __func__); - return -EIO; + } else if (guard.gc->get_direction) { + ret = guard.gc->get_direction(guard.gc, + gpio_chip_hwgpio(desc)); + if (ret < 0) + return ret; + + if (ret != GPIO_LINE_DIRECTION_IN) { + gpiod_warn(desc, + "%s: missing direction_input() operation and line is output\n", + __func__); + return -EIO; + } } if (ret == 0) { clear_bit(FLAG_IS_OUT, &desc->flags); @@ -2771,12 +2779,18 @@ static int gpiod_direction_output_raw_co gpio_chip_hwgpio(desc), val); } else { /* Check that we are in output mode if we can */ - if (guard.gc->get_direction && - guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) { - gpiod_warn(desc, - "%s: missing direction_output() operation\n", - __func__); - return -EIO; + if (guard.gc->get_direction) { + ret = guard.gc->get_direction(guard.gc, + gpio_chip_hwgpio(desc)); + if (ret < 0) + return ret; + + if (ret != GPIO_LINE_DIRECTION_OUT) { + gpiod_warn(desc, + "%s: missing direction_output() operation\n", + __func__); + return -EIO; + } } /* * If we can't actively set the direction, we are some
