| Message ID | 20240216105930.16265-1-brgl@bgdev.pl |
|---|---|
| State | New |
| Headers | show |
| Series | gpio: cdev: fix a NULL-pointer dereference with DEBUG enabled | expand |
On 16.02.2024 11:59, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > > We are actually passing the gc pointer to chip_dbg() so we have to > srcu_dereference() it. > > Fixes: 8574b5b47610 ("gpio: cdev: use correct pointer accessors with SRCU") > Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> > Closes: https://lore.kernel.org/lkml/179caa10-5f86-4707-8bb0-fe1b316326d6@samsung.com/ > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/gpio/gpiolib-cdev.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c > index 85037fa4925e..f384fa278764 100644 > --- a/drivers/gpio/gpiolib-cdev.c > +++ b/drivers/gpio/gpiolib-cdev.c > @@ -2795,8 +2795,8 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) > return ret; > > guard(srcu)(&gdev->srcu); > - > - if (!rcu_access_pointer(gdev->chip)) > + gc = srcu_dereference(gdev->chip, &gdev->srcu); > + if (!gc) > return -ENODEV; > > chip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id); Best regards
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 85037fa4925e..f384fa278764 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -2795,8 +2795,8 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) return ret; guard(srcu)(&gdev->srcu); - - if (!rcu_access_pointer(gdev->chip)) + gc = srcu_dereference(gdev->chip, &gdev->srcu); + if (!gc) return -ENODEV; chip_dbg(gc, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id);