+ mm-memfd_luo-fix-physical-address-conversion-in-put_folios-cleanup.patch added to mm-new branch

+ mm-memfd_luo-fix-physical-address-conversion-in-put_folios-cleanup.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/memfd_luo: fix physical address conversion in put_folios cleanup
has been added to the -mm mm-new branch.  Its filename is
     mm-memfd_luo-fix-physical-address-conversion-in-put_folios-cleanup.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memfd_luo-fix-physical-address-conversion-in-put_folios-cleanup.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Chenghao Duan <duanchenghao@kylinos.cn>
Subject: mm/memfd_luo: fix physical address conversion in put_folios cleanup
Date: Thu, 26 Mar 2026 16:47:25 +0800

In memfd_luo_retrieve_folios()'s put_folios cleanup path:

1. kho_restore_folio() expects a phys_addr_t (physical address) but
   receives a raw PFN (pfolio->pfn). This causes kho_restore_page() to
   check the wrong physical address (pfn << PAGE_SHIFT instead of the
   actual physical address).

2. This loop lacks the !pfolio->pfn check that exists in the main
   retrieval loop and memfd_luo_discard_folios(), which could
   incorrectly process sparse file holes where pfn=0.

Fix by converting PFN to physical address with PFN_PHYS() and adding
the !pfolio->pfn check, matching the pattern used elsewhere in this file.

This issue was identified by the AI review.
https://sashiko.dev/#/patchset/20260323110747.193569-1-duanchenghao@kylinos.cn

Link: https://lkml.kernel.org/r/20260326084727.118437-6-duanchenghao@kylinos.cn
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Cc: Haoran Jiang <jianghaoran@kylinos.cn>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memfd_luo.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/mm/memfd_luo.c~mm-memfd_luo-fix-physical-address-conversion-in-put_folios-cleanup
+++ a/mm/memfd_luo.c
@@ -484,8 +484,13 @@ put_folios:
 	 */
 	for (long j = i + 1; j < nr_folios; j++) {
 		const struct memfd_luo_folio_ser *pfolio = &folios_ser[j];
+		phys_addr_t phys;
 
-		folio = kho_restore_folio(pfolio->pfn);
+		if (!pfolio->pfn)
+			continue;
+
+		phys = PFN_PHYS(pfolio->pfn);
+		folio = kho_restore_folio(phys);
 		if (folio)
 			folio_put(folio);
 	}
_

Patches currently in -mm which might be from duanchenghao@kylinos.cn are

mm-memfd-use-folio_nr_pages-for-shmem-inode-accounting.patch
mm-memfd_luo-optimize-shmem_recalc_inode-calls-in-retrieve-path.patch
mm-memfd_luo-remove-unnecessary-memset-in-zero-size-memfd-path.patch
mm-memfd_luo-use-i_size_write-to-set-inode-size-during-retrieve.patch
mm-memfd_luo-fix-physical-address-conversion-in-put_folios-cleanup.patch
mm-memfd_luo-remove-folio-from-page-cache-when-accounting-fails.patch
mm-memfd_luo-fix-integer-overflow-in-memfd_luo_preserve_folios.patch