NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
------------[ cut here ]------------
WARNING: CPU: 0 PID: 13856 at fs/nilfs2/btree.c:2302 nilfs_btree_assign+0x983/0xbe0 fs/nilfs2/btree.c:2302
Modules linked in:
CPU: 0 UID: 0 PID: 13856 Comm: segctord Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:nilfs_btree_assign+0x983/0xbe0 fs/nilfs2/btree.c:2302
Code: 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 7f 72 32 fe 49 bf 00 00 00 00 00 fc ff df eb 9a e8 6e 72 32 fe 90 <0f> 0b 90 41 be fe ff ff ff 49 bf 00 00 00 00 00 fc ff df e9 7c ff
RSP: 0018:ffffc9000f15f4e0 EFLAGS: 00010293
RAX: ffffffff838d48c2 RBX: 00000000000000ff RCX: ffff88803641c880
RDX: 0000000000000000 RSI: 00000000fffffffe RDI: 00000000fffffffe
RBP: ffffc9000f15f610 R08: 0000000000000002 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10088c34cc R12: ffff8880425c9ff8
R13: ffffc9000f15f9a0 R14: 00000000fffffffe R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff88808d210000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 0000000011bf9000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nilfs_bmap_assign+0x92/0x170 fs/nilfs2/bmap.c:374
 nilfs_segctor_update_payload_blocknr fs/nilfs2/segment.c:1640 [inline]
 nilfs_segctor_assign fs/nilfs2/segment.c:1674 [inline]
 nilfs_segctor_do_construct+0x33b7/0x6a40 fs/nilfs2/segment.c:2133
 nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2462
 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2570 [inline]
 nilfs_segctor_thread+0x6f7/0xe00 fs/nilfs2/segment.c:2684
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>