From: David Hildenbrand <david@xxxxxxxxxx> Subject: mm/memory_hotplug.c: drop memory device reference after find_memory_block() Right now we are using find_memory_block() to get the node id for the pfn range to online. We are missing to drop a reference to the memory block device. While the device still gets unregistered via device_unregister(), resulting in no user visible problem, the device is never released via device_release(), resulting in a memory leak. Fix that by properly using a put_device(). Link: http://lkml.kernel.org/r/20190411110955.1430-1-david@xxxxxxxxxx Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Pankaj Gupta <pagupta@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Qian Cai <cai@xxxxxx> Cc: Arun KS <arunks@xxxxxxxxxxxxxx> Cc: Mathieu Malaterre <malat@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/memory_hotplug.c~mm-memory_hotplug-drop-memory-device-reference-after-find_memory_block +++ a/mm/memory_hotplug.c @@ -874,6 +874,7 @@ int __ref online_pages(unsigned long pfn */ mem = find_memory_block(__pfn_to_section(pfn)); nid = mem->nid; + put_device(&mem->dev); /* associate pfn range with the zone */ zone = move_pfn_range(online_type, nid, pfn, nr_pages); _
