------------[ cut here ]------------
kernfs: can not remove 'nr_tags', no directory
WARNING: CPU: 1 PID: 6932 at fs/kernfs/dir.c:1506 kernfs_remove_by_name_ns+0x6f/0x80 fs/kernfs/dir.c:1506
Modules linked in:
CPU: 1 PID: 6932 Comm: syz-executor626 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kernfs_remove_by_name_ns+0x6f/0x80 fs/kernfs/dir.c:1506
Code: c5 62 06 31 c0 5d 41 5c 41 5d c3 48 c7 c7 a0 e5 91 8a e8 a4 c5 62 06 b8 fe ff ff ff eb e7 48 c7 c7 20 b0 9a 88 e8 3b fd 23 06 <0f> 0b b8 fe ff ff ff eb d2 0f 1f 84 00 00 00 00 00 48 b8 00 00 00
RSP: 0018:ffffc90002dbfa90 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffffff8af80aa8 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff888afa60 RDI: fffff520005b7f44
RBP: ffffffff8af80ba0 R08: 0000000000000001 R09: ffffffff8e14b837
R10: fffffbfff1c29706 R11: 203a73666e72656b R12: ffffffff88dc12e0
R13: dffffc0000000000 R14: ffffffff88dc1200 R15: ffff88801b0d0000
FS:  00007f2a6a053700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe6b9d79e0 CR3: 000000001d944000 CR4: 0000000000350ee0
Call Trace:
 kernfs_remove_by_name include/linux/kernfs.h:593 [inline]
 remove_files+0x87/0x1a0 fs/sysfs/group.c:28
 sysfs_remove_group+0x72/0x140 fs/sysfs/group.c:289
 sysfs_remove_groups fs/sysfs/group.c:313 [inline]
 sysfs_remove_groups+0x4a/0x90 fs/sysfs/group.c:305
 __kobject_del+0x7d/0x1b0 lib/kobject.c:611
 kobject_del lib/kobject.c:643 [inline]
 kobject_del+0x32/0x50 lib/kobject.c:635
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:238 [inline]
 blk_mq_unregister_hctx block/blk-mq-sysfs.c:227 [inline]
 blk_mq_sysfs_unregister+0x1d6/0x2a0 block/blk-mq-sysfs.c:357
 __blk_mq_update_nr_hw_queues block/blk-mq.c:3640 [inline]
 blk_mq_update_nr_hw_queues+0x419/0xbe0 block/blk-mq.c:3680
 nbd_start_device+0x1a9/0xc10 drivers/block/nbd.c:1271
 nbd_start_device_ioctl drivers/block/nbd.c:1321 [inline]
 __nbd_ioctl drivers/block/nbd.c:1393 [inline]
 nbd_ioctl+0x36b/0x890 drivers/block/nbd.c:1433
 blkdev_ioctl+0x246/0x5e0 block/ioctl.c:576
 block_ioctl+0xd4/0x130 fs/block_dev.c:1658
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x11f/0x190 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f2a6a0a6329
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2a6a0532e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2a6a12a4e0 RCX: 00007f2a6a0a6329
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000007
RBP: 00007f2a6a0f7194 R08: 0000000000000002 R09: 0000000000003331
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2a6a12a4ec
R13: 00007f2a6a0532f0 R14: 00007f2a6a12a4e8 R15: 0000000000000002