[PATCH v2 1/5] mm/cma: use nth_page() in place of direct struct page manipulation.

[Zi Yan]

From: Zi Yan <ziy@xxxxxxxxxx>

When dealing with hugetlb pages, manipulating struct page pointers
directly can get to wrong struct page, since struct page is not guaranteed
to be contiguous on SPARSEMEM without VMEMMAP. Use nth_page() to handle
it properly.

Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
 mm/cma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/cma.c b/mm/cma.c
index da2967c6a223..2b2494fd6b59 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -505,7 +505,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
 	 */
 	if (page) {
 		for (i = 0; i < count; i++)
-			page_kasan_tag_reset(page + i);
+			page_kasan_tag_reset(nth_page(page, i));
 	}
 
 	if (ret && !no_warn) {
-- 
2.40.1