mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page cache are installed in the ptes. But hugepage_add_new_anon_rmap is called for them mistakenly because they're not vm_shared. This will corrupt the page->mapping used by page cache code.