From 686b4283f82cd630fafd7ca9b03dfc080b3ec8fa Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Tue, 28 Apr 2026 16:52:18 +0800 Subject: [PATCH] drivers/base/memory: fix memory block reference leak in poison accounting commit 03a2cc1756a0570f887d624cd6c535ea0cbd4951 upstream. memblk_nr_poison_inc() and memblk_nr_poison_sub() look up a memory block via find_memory_block_by_id(), which acquires a reference to the memory block device. Both helpers use the returned memory block without dropping that reference, leaking the device reference on each successful lookup. Drop the reference after updating nr_hwpoison. Link: https://lore.kernel.org/20260428085219.1316047-3-songmuchun@bytedance.com Fixes: 5033091de814 ("mm/hwpoison: introduce per-memory_block hwpoison counter") Signed-off-by: Muchun Song Reviewed-by: Miaohe Lin Acked-by: Oscar Salvador Acked-by: David Hildenbrand (Arm) Cc: Danilo Krummrich Cc: Greg Kroah-Hartman Cc: "Huang, Ying" Cc: Naoya Horiguchi Cc: "Rafael J. Wysocki" Cc: Vishal Verma Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/base/memory.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 8a13babd826c..9e413f522bd6 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -1211,8 +1211,10 @@ void memblk_nr_poison_inc(unsigned long pfn) const unsigned long block_id = pfn_to_block_id(pfn); struct memory_block *mem = find_memory_block_by_id(block_id); - if (mem) + if (mem) { atomic_long_inc(&mem->nr_hwpoison); + put_device(&mem->dev); + } } void memblk_nr_poison_sub(unsigned long pfn, long i) @@ -1220,8 +1222,10 @@ void memblk_nr_poison_sub(unsigned long pfn, long i) const unsigned long block_id = pfn_to_block_id(pfn); struct memory_block *mem = find_memory_block_by_id(block_id); - if (mem) + if (mem) { atomic_long_sub(i, &mem->nr_hwpoison); + put_device(&mem->dev); + } } static unsigned long memblk_nr_poison(struct memory_block *mem)