[PATCH 1/8] mm: memory-failure: fix potential permanently locked hpage

From: Miaohe Lin
Date: Sat Jul 08 2023 - 04:57:41 EST


If hpage isn't Hugetlb page, MF_DELAYED is returned without unlock hpage
leading to hpage permanently locked. But this shouldn't trigger in the
real world because this PageHuge() check is just for potential problems.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/memory-failure.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a6221a4bc5ea..d21ee27ad412 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1187,8 +1187,10 @@ static int me_huge_page(struct page_state *ps, struct page *p)
struct address_space *mapping;
bool extra_pins = false;

- if (!PageHuge(hpage))
+ if (!PageHuge(hpage)) {
+ unlock_page(hpage);
return MF_DELAYED;
+ }

mapping = page_mapping(hpage);
if (mapping) {
--
2.33.0