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authorJohan Hovold <johan@kernel.org>2021-03-01 10:05:18 +0100
committerBartosz Golaszewski <bgolaszewski@baylibre.com>2021-03-08 11:59:17 +0100
commita6112998ee45514def58200a7914706c0703f3d7 (patch)
tree38fa3e70278fe1c3624f6fd90240f78355de72ad /drivers/gpio
parent542104ee0cafe789cc07291b71818c143df8d623 (diff)
gpio: fix NULL-deref-on-deregistration regression
Fix a NULL-pointer deference when deregistering the gpio character device that was introduced by the recent stub-driver hack. When the new "driver" is unbound as part of deregistration, driver core clears the driver-data pointer which is used to retrieve the struct gpio_device in its release callback. Fix this by using container_of() in the release callback as should have been done all along. Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default") Cc: Saravana Kannan <saravanak@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reported-by: syzbot+d27b4c8adbbff70fbfde@syzkaller.appspotmail.com Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index adf55db080d8..6e0572515d02 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -474,7 +474,7 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodevice_release(struct device *dev)
{
- struct gpio_device *gdev = dev_get_drvdata(dev);
+ struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
list_del(&gdev->list);
ida_free(&gpio_ida, gdev->id);
@@ -605,7 +605,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
goto err_free_ida;
device_initialize(&gdev->dev);
- dev_set_drvdata(&gdev->dev, gdev);
if (gc->parent && gc->parent->driver)
gdev->owner = gc->parent->driver->owner;
else if (gc->owner)