fs: use nth_page() in place of direct struct page manipulation
authorZi Yan <ziy@nvidia.com>
Wed, 13 Sep 2023 20:12:47 +0000 (16:12 -0400)
committerAndrew Morton <akpm@linux-foundation.org>
Wed, 4 Oct 2023 17:32:29 +0000 (10:32 -0700)
commit8db0ec791f7788cd21e7f91ee5ff42c1c458d0e7
treeb3785e94b17152afa828497619f1f069e46718a9
parent1640a0ef80f6d572725f5b0330038c18e98ea168
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/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>
fs/hugetlbfs/inode.c