This is a note to let you know that I've just added the patch titled gpiolib: Fix unaligned used of reference counters to the 4.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gpiolib-fix-unaligned-used-of-reference-counters.patch and it can be found in the queue-4.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f4833b8cc7edab57d3f3033e549111a546c2e02b Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx> Date: Fri, 3 Jun 2016 19:10:02 +0200 Subject: gpiolib: Fix unaligned used of reference counters From: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx> commit f4833b8cc7edab57d3f3033e549111a546c2e02b upstream. 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). Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpio/gpiolib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -438,7 +438,6 @@ static void gpiodevice_release(struct de { 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); @@ -471,7 +470,6 @@ static int gpiochip_setup_dev(struct gpi /* 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"); @@ -742,6 +740,8 @@ void gpiochip_remove(struct gpio_chip *c * 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); Patches currently in stable-queue which might be from ricardo.ribalda@xxxxxxxxx are queue-4.6/gpiolib-fix-unaligned-used-of-reference-counters.patch queue-4.6/gpiolib-fix-null-pointer-deference.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html