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mm: use aligned address in copy_user_gigantic_page()

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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@huawei.com
Fixes: 530dd9926d ("mm: memory: improve copy_user_large_folio()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kefeng Wang 2024-10-28 22:56:56 +08:00 committed by Andrew Morton
parent 8aca2bc96c
commit f5d09de9f1
2 changed files with 5 additions and 5 deletions
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5
mm/hugetlb.c
View File

@ -5340,7 +5340,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
break; break;
} }
ret = copy_user_large_folio(new_folio, pte_folio, ret = copy_user_large_folio(new_folio, pte_folio,
ALIGN_DOWN(addr, sz), dst_vma); addr, dst_vma);
folio_put(pte_folio); folio_put(pte_folio);
if (ret) { if (ret) {
folio_put(new_folio); folio_put(new_folio);
@ -6643,8 +6643,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
*foliop = NULL; *foliop = NULL;
goto out; goto out;
} }
ret = copy_user_large_folio(folio, *foliop, ret = copy_user_large_folio(folio, *foliop, dst_addr, dst_vma);
ALIGN_DOWN(dst_addr, size), dst_vma);
folio_put(*foliop); folio_put(*foliop);
*foliop = NULL; *foliop = NULL;
if (ret) { if (ret) {

5
mm/memory.c
View File

@ -6852,13 +6852,14 @@ void folio_zero_user(struct folio *folio, unsigned long addr_hint)
} }
static int copy_user_gigantic_page(struct folio *dst, struct folio *src, static int copy_user_gigantic_page(struct folio *dst, struct folio *src,
unsigned long addr, unsigned long addr_hint,
struct vm_area_struct *vma, struct vm_area_struct *vma,
unsigned int nr_pages) unsigned int nr_pages)
{ {
int i; unsigned long addr = ALIGN_DOWN(addr_hint, folio_size(dst));
struct page *dst_page; struct page *dst_page;
struct page *src_page; struct page *src_page;
int i;
for (i = 0; i < nr_pages; i++) { for (i = 0; i < nr_pages; i++) {
dst_page = folio_page(dst, i); dst_page = folio_page(dst, i);