From: Rei Yamamoto yamamoto.rei@jp.fujitsu.com
commit bbe832b9db2e1ad21522f8f0bf02775fff8a0e0e upstream.
At present, pages not in the target zone are added to cc->migratepages list in isolate_migratepages_block(). As a result, pages may migrate between nodes unintentionally.
This would be a serious problem for older kernels without commit a984226f457f849e ("mm: memcontrol: remove the pgdata parameter of mem_cgroup_page_lruvec"), because it can corrupt the lru list by handling pages in list without holding proper lru_lock.
Avoid returning a pfn outside the target zone in the case that it is not aligned with a pageblock boundary. Otherwise isolate_migratepages_block() will handle pages not in the target zone.
Link: https://lkml.kernel.org/r/20220511044300.4069-1-yamamoto.rei@jp.fujitsu.com Fixes: 70b44595eafe ("mm, compaction: use free lists to quickly locate a migration source") Signed-off-by: Rei Yamamoto yamamoto.rei@jp.fujitsu.com Reviewed-by: Miaohe Lin linmiaohe@huawei.com Acked-by: Mel Gorman mgorman@techsingularity.net Reviewed-by: Oscar Salvador osalvador@suse.de Cc: Don Dutile ddutile@redhat.com Cc: Wonhyuk Yang vvghjk1234@gmail.com Cc: Rei Yamamoto yamamoto.rei@jp.fujitsu.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/compaction.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/mm/compaction.c +++ b/mm/compaction.c @@ -1858,6 +1858,8 @@ static unsigned long fast_find_migratebl
update_fast_start_pfn(cc, free_pfn); pfn = pageblock_start_pfn(free_pfn); + if (pfn < cc->zone->zone_start_pfn) + pfn = cc->zone->zone_start_pfn; cc->fast_search_fail = 0; found_block = true; set_pageblock_skip(freepage);