The quilt patch titled
Subject: mm/cma: use nth_page() in place of direct struct page manipulation
has been removed from the -mm tree. Its filename was
mm-cma-use-nth_page-in-place-of-direct-struct-page-manipulation.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Zi Yan <ziy@xxxxxxxxxx>
Subject: mm/cma: use nth_page() in place of direct struct page manipulation
Date: Wed, 13 Sep 2023 16:12:44 -0400
Patch series "Use nth_page() in place of direct struct page manipulation",
v3.
On SPARSEMEM without VMEMMAP, struct page is not guaranteed to be
contiguous, since each memory section's memmap might be allocated
independently. hugetlb pages can go beyond a memory section size, thus
direct struct page manipulation on hugetlb pages/subpages might give wrong
struct page. Kernel provides nth_page() to do the manipulation properly.
Use that whenever code can see hugetlb pages.
This patch (of 5):
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.
Without the fix, page_kasan_tag_reset() could reset wrong page tags,
causing a wrong kasan result. No related bug is reported. The fix
comes from code inspection.
Link: https://lkml.kernel.org/r/20230913201248.452081-1-zi.yan@xxxxxxxx
Link: https://lkml.kernel.org/r/20230913201248.452081-2-zi.yan@xxxxxxxx
Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/cma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/cma.c~mm-cma-use-nth_page-in-place-of-direct-struct-page-manipulation
+++ a/mm/cma.c
@@ -505,7 +505,7 @@ struct page *cma_alloc(struct cma *cma,
*/
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) {
_
Patches currently in -mm which might be from ziy@xxxxxxxxxx are
