syzbot

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BUG: KMSAN: uninit-value in __list_del_entry_valid+0x36f/0x410 lib/list_debug.c:54
CPU: 0 PID: 2024 Comm: kswapd0 Tainted: G        W         5.12.0-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:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 __list_del_entry_valid+0x36f/0x410 lib/list_debug.c:54
 __list_del_entry include/linux/list.h:132 [inline]
 list_del include/linux/list.h:146 [inline]
 rwsem_down_write_slowpath kernel/locking/rwsem.c:1139 [inline]
 __down_write_common+0x1c1e/0x2390 kernel/locking/rwsem.c:1261
 __down_write kernel/locking/rwsem.c:1270 [inline]
 down_write+0x2b/0x30 kernel/locking/rwsem.c:1407
 anon_vma_lock_write include/linux/rmap.h:119 [inline]
 split_huge_page_to_list+0x6c9/0x22c0 mm/huge_memory.c:2696
 shrink_page_list+0x28c4/0x7840 mm/vmscan.c:1279
 shrink_inactive_list+0x83f/0x14f0 mm/vmscan.c:1948
 shrink_list mm/vmscan.c:2170 [inline]
 shrink_lruvec+0x738/0x1480 mm/vmscan.c:2465
 shrink_node_memcgs+0x5a3/0xc60 mm/vmscan.c:2653
 shrink_node+0x1a02/0x3400 mm/vmscan.c:2770
 kswapd_shrink_node mm/vmscan.c:3513 [inline]
 balance_pgdat+0x146e/0x2570 mm/vmscan.c:3671
 kswapd+0x50b/0x8a0 mm/vmscan.c:3928
 kthread+0x521/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Local variable ----pmde.sroa.0@page_vma_mapped_walk created at:
 page_vma_mapped_walk+0xd2/0x3680 mm/page_vma_mapped.c:153
 page_vma_mapped_walk+0xd2/0x3680 mm/page_vma_mapped.c:153
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