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From:   Miaohe Lin <linmiaohe@huawei.com>
To:     <akpm@linux-foundation.org>, <naoya.horiguchi@nec.com>
CC:     <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        <linmiaohe@huawei.com>
Subject: [PATCH 1/8] mm: memory-failure: fix potential permanently locked hpage
Date:   Sat, 8 Jul 2023 16:57:37 +0800
Message-ID: <20230708085744.3599311-2-linmiaohe@huawei.com>
In-Reply-To: <20230708085744.3599311-1-linmiaohe@huawei.com>
References: <20230708085744.3599311-1-linmiaohe@huawei.com>
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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@huawei.com>
---
 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