+ mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch added to -mm tree

+ mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm/migration: fix potential invalid node access for reclaim-based migration
has been added to the -mm tree.  Its filename is
     mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/migration: fix potential invalid node access for reclaim-based migration

If we failed to setup hotplug state callbacks for mm/demotion:online in
some corner cases, node_demotion will be left uninitialized.  Invalid node
might be returned from the next_demotion_node() when doing reclaim-based
migration.  Use kcalloc to allocate node_demotion to fix the issue.

Link: https://lkml.kernel.org/r/20220318111709.60311-11-linmiaohe@huawei.com
Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/migrate.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/mm/migrate.c~mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration
+++ a/mm/migrate.c
@@ -2504,9 +2504,9 @@ static int __meminit migrate_on_reclaim_
 
 void __init migrate_on_reclaim_init(void)
 {
-	node_demotion = kmalloc_array(nr_node_ids,
-				      sizeof(struct demotion_nodes),
-				      GFP_KERNEL);
+	node_demotion = kcalloc(nr_node_ids,
+				sizeof(struct demotion_nodes),
+				GFP_KERNEL);
 	WARN_ON(!node_demotion);
 
 	hotplug_memory_notifier(migrate_on_reclaim_callback, 100);
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-shmem-make-shmem_init-return-void.patch
mm-memcg-remove-unneeded-nr_scanned.patch
mm-mremap-use-helper-mlock_future_check.patch
mm-mlock-fix-two-bugs-in-user_shm_lock.patch
mm-compaction-use-helper-isolation_suitable.patch
mm-migration-remove-unneeded-local-variable-mapping_locked.patch
mm-migration-remove-unneeded-out-label.patch
mm-migration-remove-unneeded-local-variable-page_lru.patch
mm-migration-fix-the-confusing-pagetranshuge-check.patch
mm-migration-use-helper-function-vma_lookup-in-add_page_for_migration.patch
mm-migration-use-helper-macro-min-in-do_pages_stat.patch
mm-migration-avoid-unneeded-nodemask_t-initialization.patch
mm-migration-remove-some-duplicated-codes-in-migrate_pages.patch
mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch
mm-migration-fix-possible-do_pages_stat_array-racing-with-memory-offline.patch