[to-be-updated] mm-memfd_luo-fix-integer-overflow-in-memfd_luo_preserve_folios.patch removed from -mm tree

[to-be-updated] mm-memfd_luo-fix-integer-overflow-in-memfd_luo_preserve_folios.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/memfd_luo: fix integer overflow in memfd_luo_preserve_folios
has been removed from the -mm tree.  Its filename was
     mm-memfd_luo-fix-integer-overflow-in-memfd_luo_preserve_folios.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Chenghao Duan <duanchenghao@kylinos.cn>
Subject: mm/memfd_luo: fix integer overflow in memfd_luo_preserve_folios
Date: Thu, 26 Mar 2026 16:47:27 +0800

In memfd_luo_preserve_folios(), two variables had types that could cause
silent data loss with large files:

1. 'size' was declared as 'long', truncating the 64-bit result of
   i_size_read(). On 32-bit systems a 4GB file would be truncated to 0,
   causing the function to return early and discard all data.

2. 'max_folios' was declared as 'unsigned int', causing overflow for
   sparse files larger than 4TB. For example, a 16TB+4KB file would
   calculate 0x100000001 folios but truncate to 1 when assigned to
   max_folios, causing memfd_pin_folios() to pin only the first folio.

Fix by changing both variables to 'u64' to match the types returned
by i_size_read() and the folio count calculations.

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

Link: https://lkml.kernel.org/r/20260326084727.118437-8-duanchenghao@kylinos.cn
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Haoran Jiang <jianghaoran@kylinos.cn>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memfd_luo.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/memfd_luo.c~mm-memfd_luo-fix-integer-overflow-in-memfd_luo_preserve_folios
+++ a/mm/memfd_luo.c
@@ -90,8 +90,8 @@ static int memfd_luo_preserve_folios(str
 {
 	struct inode *inode = file_inode(file);
 	struct memfd_luo_folio_ser *folios_ser;
-	unsigned int max_folios;
-	long i, size, nr_pinned;
+	u64 size, max_folios;
+	long i, nr_pinned;
 	struct folio **folios;
 	int err = -EINVAL;
 	pgoff_t offset;
_

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