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 Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Miaohe Lin <linmiaohe@xxxxxxxxxx> 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@xxxxxxxxxx Fixes: ac16ec835314 ("mm: migrate: support multiple target nodes demotion") Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- 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@xxxxxxxxxx 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