The patch titled
Subject: mm: use aligned address in copy_user_gigantic_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-use-aligned-address-in-copy_user_gigantic_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-use-aligned-address-in-copy_user_gigantic_page.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: use aligned address in copy_user_gigantic_page()
Date: Mon, 28 Oct 2024 22:56:56 +0800
In current kernel, hugetlb_wp() calls copy_user_large_folio() with the
fault address. Where the fault address may be not aligned with the huge
page size. Then, copy_user_large_folio() may call
copy_user_gigantic_page() with the address, while
copy_user_gigantic_page() requires the address to be huge page size
aligned. So, this may cause memory corruption or information leak,
addtional, use more obvious naming 'addr_hint' instead of 'addr' for
copy_user_gigantic_page().
Link: https://lkml.kernel.org/r/20241028145656.932941-2-wangkefeng.wang@xxxxxxxxxx
Fixes: 530dd9926dc1 ("mm: memory: improve copy_user_large_folio()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 5 ++---
mm/memory.c | 5 +++--
2 files changed, 5 insertions(+), 5 deletions(-)
--- a/mm/hugetlb.c~mm-use-aligned-address-in-copy_user_gigantic_page
+++ a/mm/hugetlb.c
@@ -5340,7 +5340,7 @@ again:
break;
}
ret = copy_user_large_folio(new_folio, pte_folio,
- ALIGN_DOWN(addr, sz), dst_vma);
+ addr, dst_vma);
folio_put(pte_folio);
if (ret) {
folio_put(new_folio);
@@ -6643,8 +6643,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_
*foliop = NULL;
goto out;
}
- ret = copy_user_large_folio(folio, *foliop,
- ALIGN_DOWN(dst_addr, size), dst_vma);
+ ret = copy_user_large_folio(folio, *foliop, dst_addr, dst_vma);
folio_put(*foliop);
*foliop = NULL;
if (ret) {
--- a/mm/memory.c~mm-use-aligned-address-in-copy_user_gigantic_page
+++ a/mm/memory.c
@@ -6841,13 +6841,14 @@ void folio_zero_user(struct folio *folio
}
static int copy_user_gigantic_page(struct folio *dst, struct folio *src,
- unsigned long addr,
+ unsigned long addr_hint,
struct vm_area_struct *vma,
unsigned int nr_pages)
{
- int i;
+ unsigned long addr = ALIGN_DOWN(addr_hint, folio_size(dst));
struct page *dst_page;
struct page *src_page;
+ int i;
for (i = 0; i < nr_pages; i++) {
dst_page = folio_page(dst, i);
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-remove-unused-hugepage-for-vma_alloc_folio.patch
tmpfs-dont-enable-large-folios-if-not-supported.patch
mm-huge_memory-move-file_thp_enabled-into-huge_memoryc.patch
mm-shmem-remove-__shmem_huge_global_enabled.patch
mm-use-aligned-address-in-clear_gigantic_page.patch
mm-use-aligned-address-in-copy_user_gigantic_page.patch
