+ mm-migrate-untag-addresses-when-querying-page-nodes.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/migrate: untag addresses when querying page nodes
has been added to the -mm mm-unstable branch.  Its filename is
     mm-migrate-untag-addresses-when-querying-page-nodes.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migrate-untag-addresses-when-querying-page-nodes.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Hungyu Lin <dennylin0707@gmail.com>
Subject: mm/migrate: untag addresses when querying page nodes
Date: Mon, 26 Oct 2026 19:53:29 +0000

When move_pages() is used with nodes == NULL, do_pages_stat_array() passes
each page address directly to vma_lookup().  A valid tagged address
therefore fails the VMA lookup and gets -EFAULT in its status entry,
instead of the node reported for the corresponding untagged address.

The tagged address ABI permits these pointers, and the migration path
already removes their tags.  Apply the target mm's untagging rules to the
query path as well, while holding its mmap read lock.

Link: https://lore.kernel.org/20261026195330.46757-1-dennylin0707@gmail.com
Fixes: 057d3389108e ("mm: untag user pointers passed to memory syscalls")
Signed-off-by: Hungyu Lin <dennylin0707@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/r/20260721183257.706661F000E9@smtp.kernel.org
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Ying Huang <ying.huang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <odys.yuan@gmail.com>
Cc: <stable@vger.kernel.org>
---

 mm/migrate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/migrate.c~mm-migrate-untag-addresses-when-querying-page-nodes
+++ a/mm/migrate.c
@@ -2461,7 +2461,7 @@ static void do_pages_stat_array(struct m
 	mmap_read_lock(mm);
 
 	for (i = 0; i < nr_pages; i++) {
-		unsigned long addr = (unsigned long)(*pages);
+		unsigned long addr = (unsigned long)untagged_addr_remote(mm, *pages);
 		struct vm_area_struct *vma;
 		struct folio_walk fw;
 		struct folio *folio;
_

Patches currently in -mm which might be from dennylin0707@gmail.com are

mm-page-writeback-avoid-32-bit-overflow-in-dirty-threshold-shares.patch
mm-migrate-untag-addresses-when-querying-page-nodes.patch