WARNING in schedule_bh

[butt3rflyh4ck]

Hi,
I report a bug by syzkaller and it crashes system.   and I reproduce it in the latest linux kernel.

kernel config: https://github.com/butterflyhack/syzkaller-fuzz/blob/master/v5.8.0-rc4.config

------------[ cut here ]------------
WARNING: CPU: 1 PID: 3476 at drivers/block/floppy.c:999 schedule_bh+0x5f/0x70 drivers/block/floppy.c:999
Modules linked in:
CPU: 1 PID: 3476 Comm: kworker/1:1H Not tainted 5.8.0+ #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:schedule_bh+0x5f/0x70 drivers/block/floppy.c:999
Code: 37 5c 01 fd 48 89 2d e0 d6 ce 08 5b 48 c7 c2 c0 01 2b 8a 48 8b 35 b1 db ce 08 bf 40 00 00 00 5d e9 f6 51 d9 fc e8 11 5c 01 fd <0f> 0b eb d1 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 e8 fb 5b 01 fd
RSP: 0018:ffffc90004a47900 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff8472c00f
RDX: ffff88806a131a80 RSI: ffffffff8472c03f RDI: 0000000000000007
RBP: ffffffff847392b0 R08: 0000000000000000 R09: ffffffff8a2b01c7
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88806b1ed3c0 R14: 0000000000000000 R15: ffffffff88b5e840
FS:  0000000000000000(0000) GS:ffff88806c300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004dd6e0 CR3: 000000003fa48004 CR4: 0000000000370ee0
Call Trace:
 process_fd_request drivers/block/floppy.c:2935 [inline]
 floppy_queue_rq+0x1ff/0x340 drivers/block/floppy.c:2967
 blk_mq_dispatch_rq_list+0x3a5/0x1c80 block/blk-mq.c:1387
 __blk_mq_do_dispatch_sched+0x3bc/0x890 block/blk-mq-sched.c:192
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:205 [inline]
 __blk_mq_sched_dispatch_requests+0x361/0x490 block/blk-mq-sched.c:321
 blk_mq_sched_dispatch_requests+0xfb/0x180 block/blk-mq-sched.c:347
 __blk_mq_run_hw_queue+0x13a/0x2d0 block/blk-mq.c:1525
 blk_mq_run_work_fn+0x55/0x70 block/blk-mq.c:1803
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
irq event stamp: 21581
hardirqs last  enabled at (21587): [<ffffffff815d6563>] console_trylock_spinning kernel/printk/printk.c:1776 [inline]
hardirqs last  enabled at (21587): [<ffffffff815d6563>] vprintk_emit+0x663/0x770 kernel/printk/printk.c:2028
hardirqs last disabled at (21592): [<ffffffff815d630e>] console_trylock_spinning kernel/printk/printk.c:1755 [inline]
hardirqs last disabled at (21592): [<ffffffff815d630e>] vprintk_emit+0x40e/0x770 kernel/printk/printk.c:2028
softirqs last  enabled at (21086): [<ffffffff862bfa25>] input_queue_head_incr include/linux/netdevice.h:3145 [inline]
softirqs last  enabled at (21086): [<ffffffff862bfa25>] flush_backlog+0x475/0x640 net/core/dev.c:5615
softirqs last disabled at (21082): [<ffffffff862bf5b0>] flush_backlog+0x0/0x640 arch/x86/include/asm/paravirt.h:765
---[ end trace 0faf1bfbd5b45f34 ]---
floppy0: floppy_queue_rq: timeout handler died.  old request running
floppy0: floppy_queue_rq: timeout handler died.  old request running
floppy0: floppy_queue_rq: timeout handler died.  old request running
floppy0: floppy_queue_rq: timeout handler died.  old request running

attachment is reproduce.