FAILED: patch "[PATCH] mm/hugetlb: avoid corrupting page->mapping in" failed to apply to 5.15-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From ab74ef708dc51df7cf2b8a890b9c6990fac5c0c6 Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
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@xxxxxxxxxx
Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

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);