Re: [PATCH 1/2] gpio: mt7621: report failure of devm_kasprintf()

From: Sean Wang
Date: Tue Nov 27 2018 - 02:21:10 EST


Nicholas Mc Guire <hofrat@xxxxxxxxx> æ 2018å11æ21æ éä äå10:13åéï
>
> kasprintf() may return NULL on failure of internal allocation thus the
> assigned label is not safe if not explicitly checked. On error
> mediatek_gpio_bank_probe() returns negative values so -ENOMEM in the
> (unlikely) failure case should be fine here.
>
> Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>

Acked-by: Sean Wang <sean.wang@xxxxxxxxxx>

> Fixes: 4ba9c3afda41 ("gpio: mt7621: Add a driver for MT7621")
> ---
>
> V2: The dev_err() for the unlikely case of the devm_kasprintf()
> failing was removed on request from Bartosz Golaszewski
> <bgolaszewski@xxxxxxxxxxxx>
>
> Problem located with experimental coccinelle script
>
> Patch was compile tested with: omega2p_defconfig, SOC_MT7621=y,
> GPIOLIB=y, GPIO_MT7621=y
>
> Patch is against 4.20-rc3 (localversion-next is next-20181121)
>
> drivers/gpio/gpio-mt7621.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpio/gpio-mt7621.c b/drivers/gpio/gpio-mt7621.c
> index d72af6f..1ec95bc 100644
> --- a/drivers/gpio/gpio-mt7621.c
> +++ b/drivers/gpio/gpio-mt7621.c
> @@ -244,6 +244,8 @@ mediatek_gpio_bank_probe(struct device *dev,
> rg->chip.of_xlate = mediatek_gpio_xlate;
> rg->chip.label = devm_kasprintf(dev, GFP_KERNEL, "%s-bank%d",
> dev_name(dev), bank);
> + if (!rg->chip.label)
> + return -ENOMEM;
>
> ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
> if (ret < 0) {
> --
> 2.1.4
>
>
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