The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ab74ef708dc51df7cf2b8a890b9c6990fac5c0c6 Mon Sep 17 00:00:00 2001 From: Miaohe Lin linmiaohe@huawei.com Date: Tue, 12 Jul 2022 21:05:42 +0800 Subject: [PATCH] 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.
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
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 2480ba627aa5..e070b8593b37 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6041,7 +6041,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) goto out_release_unlock;
- if (vm_shared) { + if (page_in_pagecache) { page_dup_file_rmap(page, true); } else { ClearHPageRestoreReserve(page);