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| author |   Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> | 2016-06-03 19:10:02 +0200 |
|---|---|---|
| committer |   Linus Walleij <linus.walleij@linaro.org> | 2016-06-08 10:40:29 +0200 |
| commit | f4833b8cc7edab57d3f3033e549111a546c2e02b (patch) | |
| tree | 9ec107aa22c29db288c6444ee21d3f1be5521266 /drivers/gpio/gpiolib.c | |
| parent | gpiolib: Fix NULL pointer deference (diff) | |
| download | wireguard-linux-f4833b8cc7edab57d3f3033e549111a546c2e02b.tar.xz wireguard-linux-f4833b8cc7edab57d3f3033e549111a546c2e02b.zip | |
gpiolib: Fix unaligned used of reference counters
gpiolib relies on the reference counters to clean up the gpio_device
structure.
Although the number of get/put is properly aligned on gpiolib.c
itself, it does not take into consideration how the referece counters
are affected by other external functions such as cdev_add and device_add.
Because of this, after the last call to put_device, the reference counter
has a value of +3, therefore never calling gpiodevice_release.
Due to the fact that some of the device has already been cleaned on
gpiochip_remove, the library will end up OOPsing the kernel (e.g. a call
to of_gpiochip_find_and_xlate).
Cc: stable@vger.kernel.org
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a2c31a5a677f..58d822d7e8da 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -449,7 +449,6 @@ static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = dev_get_drvdata(dev); - cdev_del(&gdev->chrdev); list_del(&gdev->list); ida_simple_remove(&gpio_ida, gdev->id); kfree(gdev->label); @@ -482,7 +481,6 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) /* From this point, the .release() function cleans up gpio_device */ gdev->dev.release = gpiodevice_release; - get_device(&gdev->dev); pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n", __func__, gdev->base, gdev->base + gdev->ngpio - 1, dev_name(&gdev->dev), gdev->chip->label ? : "generic"); @@ -770,6 +768,8 @@ void gpiochip_remove(struct gpio_chip *chip) * be removed, else it will be dangling until the last user is * gone. */ + cdev_del(&gdev->chrdev); + device_del(&gdev->dev); put_device(&gdev->dev); } EXPORT_SYMBOL_GPL(gpiochip_remove); |