[merged mm-stable] mm-page_alloc-make-sure-tail_page-private-is-zero-at-page-free-time.patch removed from -mm tree

[merged mm-stable] mm-page_alloc-make-sure-tail_page-private-is-zero-at-page-free-time.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/page_alloc: make sure tail_page->private is zero at page free time
has been removed from the -mm tree.  Its filename was
     mm-page_alloc-make-sure-tail_page-private-is-zero-at-page-free-time.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@nvidia.com>
Subject: mm/page_alloc: make sure tail_page->private is zero at page free time
Date: Thu, 09 Jul 2026 14:06:04 -0400

Any code using tail_page->private of a folio, a compound page or a
high-order page is supposed to reset it after use, otherwise ->private
data can leak to new page user and cause unexpected issues.  Add a
bad_page() check at page free path for it.

Link: https://lore.kernel.org/20260709-keep-subpage-private-zero-at-free-v3-4-7e4fe155f5b9@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |   14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

--- a/mm/page_alloc.c~mm-page_alloc-make-sure-tail_page-private-is-zero-at-page-free-time
+++ a/mm/page_alloc.c
@@ -1377,15 +1377,23 @@ static __always_inline bool __free_pages
 #endif
 		}
 		for (i = 1; i < (1 << order); i++) {
+			struct page *tail_page = page + i;
+
 			if (compound)
-				bad += free_tail_page_prepare(page, page + i);
+				bad += free_tail_page_prepare(page, tail_page);
 			if (is_check_pages_enabled()) {
-				if (free_page_is_bad(page + i)) {
+				if (free_page_is_bad(tail_page)) {
+					bad++;
+					continue;
+				}
+
+				if (tail_page->private) {
+					bad_page(tail_page, "nonzero private");
 					bad++;
 					continue;
 				}
 			}
-			(page + i)->flags.f &= ~PAGE_FLAGS_CHECK_AT_PREP;
+			tail_page->flags.f &= ~PAGE_FLAGS_CHECK_AT_PREP;
 		}
 	}
 	if (folio_test_anon(folio)) {
_

Patches currently in -mm which might be from ziy@nvidia.com are

mm-huge_memory-use-folios-memcg-inside-__folio_split.patch
xarray-honor-xa_flags_account-in-xas_split_alloc.patch