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 <[email protected]>
Fixes: 4ba9c3afda41 ("gpio: mt7621: Add a driver for MT7621")
---
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 | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpio/gpio-mt7621.c b/drivers/gpio/gpio-mt7621.c
index d72af6f..42f0c67 100644
--- a/drivers/gpio/gpio-mt7621.c
+++ b/drivers/gpio/gpio-mt7621.c
@@ -244,6 +244,10 @@ 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) {
+ dev_err(dev, "Could not allocate label\n");
+ return -ENOMEM;
+ }
ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
if (ret < 0) {
--
2.1.4
śr., 21 lis 2018 o 17:39 Nicholas Mc Guire <[email protected]> napisał(a):
>
> 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 <[email protected]>
> Fixes: 4ba9c3afda41 ("gpio: mt7621: Add a driver for MT7621")
> ---
>
> 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 | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpio/gpio-mt7621.c b/drivers/gpio/gpio-mt7621.c
> index d72af6f..42f0c67 100644
> --- a/drivers/gpio/gpio-mt7621.c
> +++ b/drivers/gpio/gpio-mt7621.c
> @@ -244,6 +244,10 @@ 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) {
> + dev_err(dev, "Could not allocate label\n");
No need for an error message here, an -ENOMEM says enough.
Bart
> + return -ENOMEM;
> + }
>
> ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
> if (ret < 0) {
> --
> 2.1.4
>
On Wed, Nov 21, 2018 at 05:43:43PM +0100, Bartosz Golaszewski wrote:
> ??r., 21 lis 2018 o 17:39 Nicholas Mc Guire <[email protected]> napisa??(a):
> >
> > 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 <[email protected]>
> > Fixes: 4ba9c3afda41 ("gpio: mt7621: Add a driver for MT7621")
> > ---
> >
> > 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 | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/gpio/gpio-mt7621.c b/drivers/gpio/gpio-mt7621.c
> > index d72af6f..42f0c67 100644
> > --- a/drivers/gpio/gpio-mt7621.c
> > +++ b/drivers/gpio/gpio-mt7621.c
> > @@ -244,6 +244,10 @@ 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) {
> > + dev_err(dev, "Could not allocate label\n");
>
> No need for an error message here, an -ENOMEM says enough.
>
I just thought its more consistent with the rest of
the code - and as it is a highly unlikely event it would
probably be hard to pinpoint as some of the other functions
can return -ENOMEM (but with a message).
....and the call site of mediatek_gpio_bank_probe() actually
currently ignores the return value so the -ENOMEM would go
unnoticed which is a bug as well - patch for that a bit later.
anyway fine with me - I?ll send a V2 and drop the dev_err() here.
thx!
hofrat
> Bart
>
> > + return -ENOMEM;
> > + }
> >
> > ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
> > if (ret < 0) {
> > --
> > 2.1.4
> >