This is a note to let you know that I've just added the patch titled gpio: gpiolib-of: Fix refcount bugs in of_mm_gpiochip_add_data() to the 5.4-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: gpio-gpiolib-of-fix-refcount-bugs-in-of_mm_gpiochip_.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f994b259e7ea9ab3fef589a92772267b3721f864 Author: Liang He <windhl@xxxxxxx> Date: Mon Jul 11 20:52:38 2022 +0800 gpio: gpiolib-of: Fix refcount bugs in of_mm_gpiochip_add_data() [ Upstream commit 5d07a692f9562f9c06e62cce369e9dd108173a0f ] We should use of_node_get() when a new reference of device_node is created. It is noted that the old reference stored in 'mm_gc->gc.of_node' should also be decreased. This patch is based on the fact that there is a call site in function 'qe_add_gpiochips()' of src file 'drivers\soc\fsl\qe\gpio.c'. In this function, of_mm_gpiochip_add_data() is contained in an iteration of for_each_compatible_node() which will automatically increase and decrease the refcount. So we need additional of_node_get() for the reference escape in of_mm_gpiochip_add_data(). Fixes: a19e3da5bc5f ("of/gpio: Kill of_gpio_chip and add members directly to gpio_chip") Signed-off-by: Liang He <windhl@xxxxxxx> Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index b1dcd2dd52e6..73807c897391 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -734,7 +734,8 @@ int of_mm_gpiochip_add_data(struct device_node *np, if (mm_gc->save_regs) mm_gc->save_regs(mm_gc); - mm_gc->gc.of_node = np; + of_node_put(mm_gc->gc.of_node); + mm_gc->gc.of_node = of_node_get(np); ret = gpiochip_add_data(gc, data); if (ret) @@ -742,6 +743,7 @@ int of_mm_gpiochip_add_data(struct device_node *np, return 0; err2: + of_node_put(np); iounmap(mm_gc->regs); err1: kfree(gc->label);