From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> commit 8aca2bc96c833ba695ede7a45ad7784c836a262e upstream. In current kernel, hugetlb_no_page() calls folio_zero_user() with the fault address. Where the fault address may be not aligned with the huge page size. Then, folio_zero_user() may call clear_gigantic_page() with the address, while clear_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 clear_gigantic_page(). Link: https://lkml.kernel.org/r/20241028145656.932941-1-wangkefeng.wang@xxxxxxxxxx Fixes: 78fefd04c123 ("mm: memory: convert clear_huge_page() to folio_zero_user()") Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Muchun Song <muchun.song@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/hugetlbfs/inode.c | 2 +- mm/memory.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -893,7 +893,7 @@ static long hugetlbfs_fallocate(struct f error = PTR_ERR(folio); goto out; } - folio_zero_user(folio, ALIGN_DOWN(addr, hpage_size)); + folio_zero_user(folio, addr); __folio_mark_uptodate(folio); error = hugetlb_add_to_page_cache(folio, mapping, index); if (unlikely(error)) { --- a/mm/memory.c +++ b/mm/memory.c @@ -6780,9 +6780,10 @@ static inline int process_huge_page( return 0; } -static void clear_gigantic_page(struct folio *folio, unsigned long addr, +static void clear_gigantic_page(struct folio *folio, unsigned long addr_hint, unsigned int nr_pages) { + unsigned long addr = ALIGN_DOWN(addr_hint, folio_size(folio)); int i; might_sleep(); Patches currently in stable-queue which might be from wangkefeng.wang@xxxxxxxxxx are queue-6.12/mm-use-aligned-address-in-copy_user_gigantic_page.patch queue-6.12/mm-use-aligned-address-in-clear_gigantic_page.patch
