From: Zi Yan <ziy@nvidia.com> stable inclusion from stable-v6.6.3 commit cc64f5ea94442d8fb663ead545ccfb6976cc2a11 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 8db0ec791f7788cd21e7f91ee5ff42c1c458d0e7 upstream. 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/20230913201248.452081-5-zi.yan@sent.com Fixes: 38c1ddbde6c6 ("hugetlbfs: improve read HWPOISON hugepage") Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/hugetlbfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index cb6a5ea74cda..b0edf5fe8132 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; } } -- 2.20.1