hugetlbfs: don't access uninitialized memmaps in pfn_range_valid_gigantic()

[mirror_ubuntu-bionic-kernel.git] / mm / hugetlb.c

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d8faf0b8b8e0dad84ae7a4d702ee280c96187d8b..d9b59501c8a307c7d5b1e6e1eeb66e23847c178b 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1081,11 +1081,10 @@ static bool pfn_range_valid_gigantic(struct zone *z,
        struct page *page;
 
        for (i = start_pfn; i < end_pfn; i++) {
-               if (!pfn_valid(i))
+               page = pfn_to_online_page(i);
+               if (!page)
                        return false;
 
-               page = pfn_to_page(i);
-
                if (page_zone(page) != z)
                        return false;