FAILED: patch "[PATCH] mm/huge_memory: update file PMD counter before folio_put()" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 8d878059924f12c1bc24556a92ec56add74de3c8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026061512-encrypt-banking-e175@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 8d878059924f12c1bc24556a92ec56add74de3c8 Mon Sep 17 00:00:00 2001
From: Yin Tirui <yintirui@huawei.com>
Date: Tue, 26 May 2026 18:13:37 +0800
Subject: [PATCH] mm/huge_memory: update file PMD counter before folio_put()

__split_huge_pmd_locked() updates the file/shmem RSS counter after
dropping the PMD mapping's folio reference.  If folio_put() drops the last
reference, mm_counter_file() can later read freed folio state via
folio_test_swapbacked().

Move the counter update before folio_put().

Link: https://lore.kernel.org/20260526101337.1984081-1-yintirui@huawei.com
Fixes: fadae2953072 ("thp: use mm_file_counter to determine update which rss counter")
Signed-off-by: Yin Tirui <yintirui@huawei.com>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: David Hildenbrand (arm) <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chen Jun <chenjun102@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1f78b73a0ca4..653f2dc03403 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3133,7 +3133,9 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
 			if (!folio_test_referenced(folio) && pmd_young(old_pmd))
 				folio_set_referenced(folio);
 			folio_remove_rmap_pmd(folio, page, vma);
+			add_mm_counter(mm, mm_counter_file(folio), -HPAGE_PMD_NR);
 			folio_put(folio);
+			return;
 		}
 		add_mm_counter(mm, mm_counter_file(folio), -HPAGE_PMD_NR);
 		return;