From 8aca2bc96c833ba695ede7a45ad7784c836a262e Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Mon, 28 Oct 2024 22:56:55 +0800 Subject: [PATCH] mm: use aligned address in clear_gigantic_page() 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@huawei.com Fixes: 78fefd04c123 ("mm: memory: convert clear_huge_page() to folio_zero_user()") Signed-off-by: Kefeng Wang Reviewed-by: "Huang, Ying" Reviewed-by: David Hildenbrand Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Signed-off-by: Andrew Morton --- fs/hugetlbfs/inode.c | 2 +- mm/memory.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 90f883d6b8fd..fc1ae5132127 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -825,7 +825,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, 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)) { diff --git a/mm/memory.c b/mm/memory.c index 75c2dfd04f72..84864387f965 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6815,9 +6815,10 @@ 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();