4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> commit b6eae0f61db27748606cc00dafcfd1e2c032f0a5 upstream. Unlike asynchronous initialization in the core we have not yet associated the device with the parent, and as such the device doesn't hold a reference to the parent. In order to resolve that we should be holding a reference on the parent until the asynchronous initialization has completed. Cc: <stable@xxxxxxxxxxxxxxx> Fixes: 4d88a97aa9e8 ("libnvdimm: ...base ... infrastructure") Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/nvdimm/bus.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/nvdimm/bus.c +++ b/drivers/nvdimm/bus.c @@ -158,6 +158,8 @@ static void nd_async_device_register(voi put_device(dev); } put_device(dev); + if (dev->parent) + put_device(dev->parent); } static void nd_async_device_unregister(void *d, async_cookie_t cookie) @@ -175,6 +177,8 @@ static void nd_async_device_unregister(v void __nd_device_register(struct device *dev) { dev->bus = &nvdimm_bus_type; + if (dev->parent) + get_device(dev->parent); get_device(dev); async_schedule_domain(nd_async_device_register, dev, &nd_async_domain);