From: Miaohe Lin linmiaohe@huawei.com

commit ab74ef708dc51df7cf2b8a890b9c6990fac5c0c6 upstream.

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.

Link: https://lkml.kernel.org/r/20220712130542.18836-1-linmiaohe@huawei.com Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl") Signed-off-by: Miaohe Lin linmiaohe@huawei.com Reviewed-by: Mike Kravetz mike.kravetz@oracle.com Cc: Axel Rasmussen axelrasmussen@google.com Cc: Peter Xu peterx@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Axel Rasmussen axelrasmussen@google.com --- mm/hugetlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 405793b8cf0d..d61b665c45d6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5371,7 +5371,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, if (!huge_pte_none(huge_ptep_get(dst_pte))) goto out_release_unlock;

- if (vm_shared) { + if (page_in_pagecache) { page_dup_rmap(page, true); } else { ClearHPageRestoreReserve(page);