------------[ cut here ]------------
kernfs: can not remove 'nr_tags', no directory
WARNING: CPU: 0 PID: 17350 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x65/0xa0 fs/kernfs/dir.c:1503
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 17350 Comm: syz-executor.2 Not tainted 5.2.0-rc6+ #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 panic+0x28a/0x7c9 kernel/panic.c:219
 __warn+0x216/0x220 kernel/panic.c:576
 report_bug+0x190/0x290 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x450 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:kernfs_remove_by_name_ns+0x65/0xa0 fs/kernfs/dir.c:1503
Code: 48 85 c0 74 2e e8 2b ff 99 ff 4c 89 f7 e8 53 e7 ff ff eb 24 e8 1c ff 99 ff 48 c7 c7 b9 32 5e 88 4c 89 fe 31 c0 e8 0b d1 6b ff <0f> 0b b8 fe ff ff ff eb 1d e8 fd fe 99 ff 31 db 4d 85 f6 0f 95 c3
RSP: 0018:ffff88809e40f490 EFLAGS: 00010246
RAX: 905f100b25ebdf00 RBX: 0000000000000000 RCX: 0000000000040000
RDX: ffffc9000a61d000 RSI: 00000000000130ef RDI: 00000000000130f0
RBP: ffff88809e40f4a8 R08: ffffffff815e87e4 R09: ffffed1015d46063
R10: ffffed1015d46063 R11: 1ffff11015d46062 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff8866090a
 kernfs_remove_by_name include/linux/kernfs.h:567 [inline]
 remove_files fs/sysfs/group.c:27 [inline]
 sysfs_remove_group+0x10c/0x260 fs/sysfs/group.c:264
 sysfs_remove_groups+0x63/0xb0 fs/sysfs/group.c:288
 kobject_del+0x8b/0x1f0 lib/kobject.c:619
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:243 [inline]
 blk_mq_sysfs_unregister+0x225/0x310 block/blk-mq-sysfs.c:373
 __blk_mq_update_nr_hw_queues block/blk-mq.c:3286 [inline]
 blk_mq_update_nr_hw_queues+0x63c/0xe60 block/blk-mq.c:3321
 nbd_start_device+0x173/0xa00 drivers/block/nbd.c:1166
 nbd_start_device_ioctl drivers/block/nbd.c:1207 [inline]
 __nbd_ioctl drivers/block/nbd.c:1278 [inline]
 nbd_ioctl+0x3ed/0xab0 drivers/block/nbd.c:1318
 __blkdev_driver_ioctl block/ioctl.c:304 [inline]
 blkdev_ioctl+0x917/0x2c10 block/ioctl.c:606
 block_ioctl+0xbd/0x100 fs/block_dev.c:1930
 do_vfs_ioctl+0x7d4/0x1890 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718
 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459519
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f89db608c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000459519
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f89db6096d4
R13: 00000000004c2cd4 R14: 00000000004d6050 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..