On Fri, Feb 26, 2021 at 6:55 AM Johan Hovold johan@kernel.org wrote:

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 Signed-off-by: Johan Hovold johan@kernel.org

---

drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e1016bc8cf14..42bdc55a15f9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);

•   unsigned long flags;
  
  

•   spin_lock_irqsave(&gpio_lock, flags);
    list_del(&gdev->list);
  

•   spin_unlock_irqrestore(&gpio_lock, flags);
  

Reviewed-by: Saravana Kannan saravanak@google.com

-Saravana

    ida_free(&gpio_ida, gdev->id);
    kfree_const(gdev->label);
    kfree(gdev->descs);

-- 2.26.2