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mm: use aligned address in clear_gigantic_page()

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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: 78fefd04c1 ("mm: memory: convert clear_huge_page() to folio_zero_user()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.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 22:56:55 +08:00 committed by Andrew Morton
parent dad2dc9c92
commit 8aca2bc96c
2 changed files with 3 additions and 2 deletions
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2
fs/hugetlbfs/inode.c
View File

@ -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)) {

3
mm/memory.c
View File

@ -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();