[PATCH v1] hugetlb: pass head page to remove_hugetlb_page()

From: Naoya Horiguchi
Date: Wed May 26 2021 - 19:53:15 EST


From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>

When memory_failure() or soft_offline_page() is called on a tail page of
some hugetlb page, "BUG: unable to handle page fault" error can be
triggered.

remove_hugetlb_page() dereferences page->lru, so it's assumed that the
page points to a head page, but one of the caller,
dissolve_free_huge_page(), provides remove_hugetlb_page() with 'page'
which could be a tail page. So pass 'head' to it, instead.

Fixes: 6eb4e88a6d27 ("hugetlb: create remove_hugetlb_page() to separate functionality")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
---
mm/hugetlb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git v5.13-rc3/mm/hugetlb.c v5.13-rc3_patched/mm/hugetlb.c
index 95918f410c0f..470f7b5b437e 100644
--- v5.13-rc3/mm/hugetlb.c
+++ v5.13-rc3_patched/mm/hugetlb.c
@@ -1793,7 +1793,7 @@ int dissolve_free_huge_page(struct page *page)
SetPageHWPoison(page);
ClearPageHWPoison(head);
}
- remove_hugetlb_page(h, page, false);
+ remove_hugetlb_page(h, head, false);
h->max_huge_pages--;
spin_unlock_irq(&hugetlb_lock);
update_and_free_page(h, head);
--
2.25.1