From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Johan Hovold johan@kernel.org
commit cf25ef6b631c6fc6c0435fc91eba8734cca20511 upstream.
Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") Cc: stable@vger.kernel.org # 4.6 Reviewed-by: Saravana Kannan saravanak@google.com Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com [ johan: adjust context to 5.11 ] Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -469,8 +469,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = dev_get_drvdata(dev); + unsigned long flags;
+ spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); + spin_unlock_irqrestore(&gpio_lock, flags); + ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); kfree(gdev->descs);