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authorZi Yan <[email protected]>2023-09-13 16:12:47 -0400
committerAndrew Morton <[email protected]>2023-10-04 10:32:29 -0700
commit8db0ec791f7788cd21e7f91ee5ff42c1c458d0e7 (patch)
treeb3785e94b17152afa828497619f1f069e46718a9
parent1640a0ef80f6d572725f5b0330038c18e98ea168 (diff)
fs: use nth_page() in place of direct struct page manipulation
When dealing with hugetlb pages, struct page is not guaranteed to be contiguous on SPARSEMEM without VMEMMAP. Use nth_page() to handle it properly. Without the fix, a wrong subpage might be checked for HWPoison, causing wrong number of bytes of a page copied to user space. No bug is reported. The fix comes from code inspection. Link: https://lkml.kernel.org/r/[email protected] Fixes: 38c1ddbde6c6 ("hugetlbfs: improve read HWPOISON hugepage") Signed-off-by: Zi Yan <[email protected]> Reviewed-by: Muchun Song <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Mike Rapoport (IBM) <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
-rw-r--r--fs/hugetlbfs/inode.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 316c4cebd3f3..60fce26ff937 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -295,7 +295,7 @@ static size_t adjust_range_hwpoison(struct page *page, size_t offset, size_t byt
size_t res = 0;
/* First subpage to start the loop. */
- page += offset / PAGE_SIZE;
+ page = nth_page(page, offset / PAGE_SIZE);
offset %= PAGE_SIZE;
while (1) {
if (is_raw_hwpoison_page_in_hugepage(page))
@@ -309,7 +309,7 @@ static size_t adjust_range_hwpoison(struct page *page, size_t offset, size_t byt
break;
offset += n;
if (offset == PAGE_SIZE) {
- page++;
+ page = nth_page(page, 1);
offset = 0;
}
}