7.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gregory Price <gourry@gourry.net>

[ Upstream commit ab7ace574f3da7f167fe1883116480a00c52150c ]

madvise_cold_or_pageout_pte_range() resolves the folio backing a PMD via
pmd_folio() and ages or reclaims it without checking for zone device
memory.

The surrounding guards do not cover every zone device case:

  - can_madv_lru_vma() excludes VM_PFNMAP and VM_HUGETLB VMAs
    (so device DAX is filtered)

  - !pmd_present() branch above rejects device-private and
    migration entries, which are non-present.

  - A present zone device PMD - e.g. a device-coherent THP - is
    not filtered by any of these, nor by pmd_folio() (unlike
    vm_normal_page_pmd(), it performs no special/pfnmap check),
    and would be aged or paged out here.

Skip ZONE_DEVICE folios explicitly during MADV_COLD/PAGEOUT.

Link: https://lore.kernel.org/20260817220810.1175596-3-gourry@gourry.net
Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages")
Signed-off-by: Gregory Price (Meta) <gourry@gourry.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Balbir Singh <balbirs@nvidia.com>
Tested-by: Lance Yang <lance.yang@linux.dev>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/madvise.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/madvise.c b/mm/madvise.c
index eeee82cf2b3f4..73c2901b9adbf 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -404,6 +404,9 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
 
 		folio = pmd_folio(orig_pmd);
 
+		if (folio_is_zone_device(folio))
+			goto huge_unlock;
+
 		/* Do not interfere with other mappings of this folio */
 		if (folio_maybe_mapped_shared(folio))
 			goto huge_unlock;
-- 
2.53.0