BUG: spinlock bad magic in page_vma_mapped

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	BUG: spinlock bad magic in page_vma_mapped_walk mm				1	1993d	1993d	0/26	auto-closed as invalid on 2019/05/09 16:29

BUG: spinlock bad magic on CPU#1, kcompactd0/1660
 lock: 0xffff8880001390c0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
CPU: 1 PID: 1660 Comm: kcompactd0 Not tainted 5.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 do_raw_spin_lock+0x216/0x2b0 kernel/locking/spinlock_debug.c:112
 spin_lock include/linux/spinlock.h:354 [inline]
 map_pte mm/page_vma_mapped.c:52 [inline]
 page_vma_mapped_walk+0xd87/0x24f0 mm/page_vma_mapped.c:261
 remove_migration_pte+0x141/0xed0 mm/migrate.c:188
 rmap_walk_anon+0x2ab/0x660 mm/rmap.c:2294
 rmap_walk+0x12a/0x190 mm/rmap.c:2365
 remove_migration_ptes mm/migrate.c:280 [inline]
 __unmap_and_move mm/migrate.c:1072 [inline]
 unmap_and_move mm/migrate.c:1136 [inline]
 migrate_pages+0x1027/0x3970 mm/migrate.c:1411
 compact_zone+0x1ab9/0x3860 mm/compaction.c:2399
 proactive_compact_node+0x103/0x1c0 mm/compaction.c:2653
 kcompactd+0x9a3/0xd10 mm/compaction.c:2923
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295