| Message ID | 20190228104323.GA18288@mark-devvm |
|---|---|
| State | New |
| Headers | show |
| Series | gpio: pca953x: Fix dereference of irq data in shutdown | expand |
Hi Mark, czw., 28 lut 2019 o 11:45 Mark Walton <mark.walton@serialtek.com> napisał(a): > > If a PCA953x gpio was used as an interrupt and then released, > the shutdown function was trying to extract the pca953x_chip > pointer directly from the irq_data, but in reality was getting > the gpio_chip structure. > > The net effect was that the subsequent writes to the data > structure corrupted data in the gpio_chip structure, which wasn't > immediately obvious until attempting to use the GPIO again in the > future, at which point the kernel panics. > > This fix correctly extracts the pca953x_chip structure via the > gpio_chip structure, as is correctly done in the other irq > functions. > > Signed-off-by: Mark Walton <mark.walton@serialtek.com> please add the Fixes: tag - this should go into stable. Bart > --- > drivers/gpio/gpio-pca953x.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c > index caf7dd1..6bd55a4 100644 > --- a/drivers/gpio/gpio-pca953x.c > +++ b/drivers/gpio/gpio-pca953x.c > @@ -659,7 +659,8 @@ static int pca953x_irq_set_type(struct irq_data *d, unsigned int type) > > static void pca953x_irq_shutdown(struct irq_data *d) > { > - struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); > + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); > + struct pca953x_chip *chip = gpiochip_get_data(gc); > u8 mask = 1 << (d->hwirq % BANK_SZ); > > chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask; > -- > 2.7.4 >
Hi Bart, > -----Original Message----- > From: Bartosz Golaszewski <bgolaszewski@baylibre.com> > Sent: 28 February 2019 13:37 > To: Mark Walton <mark.walton@serialtek.com> > Cc: Linus Walleij <linus.walleij@linaro.org>; Marek Vasut > <marek.vasut@gmail.com>; linux-gpio@vger.kernel.org > Subject: Re: [PATCH] gpio: pca953x: Fix dereference of irq data in shutdown > > Hi Mark, > > czw., 28 lut 2019 o 11:45 Mark Walton <mark.walton@serialtek.com> > napisał(a): > > > > If a PCA953x gpio was used as an interrupt and then released, the > > shutdown function was trying to extract the pca953x_chip pointer > > directly from the irq_data, but in reality was getting the gpio_chip > > structure. > > > > The net effect was that the subsequent writes to the data structure > > corrupted data in the gpio_chip structure, which wasn't immediately > > obvious until attempting to use the GPIO again in the future, at which > > point the kernel panics. > > > > This fix correctly extracts the pca953x_chip structure via the > > gpio_chip structure, as is correctly done in the other irq functions. > > > > Signed-off-by: Mark Walton <mark.walton@serialtek.com> > > please add the Fixes: tag - this should go into stable. OK sure, I'll resubmit this with the Fixes: tag and cc stable. Mark > > Bart > > > --- > > drivers/gpio/gpio-pca953x.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c > > index caf7dd1..6bd55a4 100644 > > --- a/drivers/gpio/gpio-pca953x.c > > +++ b/drivers/gpio/gpio-pca953x.c > > @@ -659,7 +659,8 @@ static int pca953x_irq_set_type(struct irq_data > > *d, unsigned int type) > > > > static void pca953x_irq_shutdown(struct irq_data *d) { > > - struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); > > + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); > > + struct pca953x_chip *chip = gpiochip_get_data(gc); > > u8 mask = 1 << (d->hwirq % BANK_SZ); > > > > chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask; > > -- > > 2.7.4 > >
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index caf7dd1..6bd55a4 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -659,7 +659,8 @@ static int pca953x_irq_set_type(struct irq_data *d, unsigned int type) static void pca953x_irq_shutdown(struct irq_data *d) { - struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct pca953x_chip *chip = gpiochip_get_data(gc); u8 mask = 1 << (d->hwirq % BANK_SZ); chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
If a PCA953x gpio was used as an interrupt and then released, the shutdown function was trying to extract the pca953x_chip pointer directly from the irq_data, but in reality was getting the gpio_chip structure. The net effect was that the subsequent writes to the data structure corrupted data in the gpio_chip structure, which wasn't immediately obvious until attempting to use the GPIO again in the future, at which point the kernel panics. This fix correctly extracts the pca953x_chip structure via the gpio_chip structure, as is correctly done in the other irq functions. Signed-off-by: Mark Walton <mark.walton@serialtek.com> --- drivers/gpio/gpio-pca953x.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)