]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commitdiff
gpio: fix gpio-device list corruption
authorJohan Hovold <johan@kernel.org>
Mon, 1 Mar 2021 09:05:19 +0000 (10:05 +0100)
committerBartosz Golaszewski <bgolaszewski@baylibre.com>
Mon, 8 Mar 2021 10:59:17 +0000 (11:59 +0100)
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>
drivers/gpio/gpiolib.c

index 6e0572515d02932ef79fcab3c8d2cd62bfc39671..4253837f870b1798e3b987db991c1fb119f7406a 100644 (file)
@@ -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);
+
        ida_free(&gpio_ida, gdev->id);
        kfree_const(gdev->label);
        kfree(gdev->descs);