------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(1)
WARNING: kernel/locking/lockdep.c:238 at 0x0, CPU#2: syz.4.3873/20013
Modules linked in:
CPU: 2 UID: 0 PID: 20013 Comm: syz.4.3873 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:hlock_class kernel/locking/lockdep.c:238 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:227 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline]
RIP: 0010:__lock_acquire+0x1226/0x22f0 kernel/locking/lockdep.c:5187
Code: a3 9a 87 8d 67 48 0f b9 3a 4c 8b 54 24 10 4c 8b 4c 24 08 44 8b 1c 24 e9 05 f9 ff ff 48 8d 3d 81 81 d0 0e 48 c7 c6 a3 9a 87 8d <67> 48 0f b9 3a 4c 8b 54 24 10 4c 8b 4c 24 08 44 8b 1c 24 e9 1b f9
RSP: 0018:ffffc90006a775c0 EFLAGS: 00010046
RAX: 0000000000000001 RBX: ffff888023260b80 RCX: ffffc90029666000
RDX: 0000000000000000 RSI: ffffffff8d879aa3 RDI: ffffffff90693360
RBP: ffff888023260000 R08: 0000000000000001 R09: f580fa0f0b051a50
R10: ffff888023260b30 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff8b18dde8
FS:  0000000000000000(0000) GS:ffff888097ba5000(0063) knlGS:00000000f5445b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7330bb4 CR3: 0000000057b79000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
 down_write+0x92/0x200 kernel/locking/rwsem.c:1590
 kernfs_remove_by_name_ns+0x3d/0x100 fs/kernfs/dir.c:1712
 sysfs_remove_file include/linux/sysfs.h:770 [inline]
 driver_remove_file drivers/base/driver.c:201 [inline]
 driver_remove_file+0x4a/0x60 drivers/base/driver.c:197
 remove_bind_files drivers/base/bus.c:605 [inline]
 bus_remove_driver+0x224/0x2c0 drivers/base/bus.c:743
 driver_unregister+0x76/0xb0 drivers/base/driver.c:277
 comedi_device_detach_locked+0x12f/0xa50 drivers/comedi/drivers.c:207
 do_devconfig_ioctl+0x555/0x710 drivers/comedi/comedi_fops.c:848
 comedi_unlocked_ioctl+0x165d/0x2ee0 drivers/comedi/comedi_fops.c:2178
 comedi_compat_ioctl+0x1d0/0x960 drivers/comedi/comedi_fops.c:3249
 __do_compat_sys_ioctl fs/ioctl.c:695 [inline]
 __se_compat_sys_ioctl fs/ioctl.c:638 [inline]
 __ia32_compat_sys_ioctl+0x242/0x370 fs/ioctl.c:638
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f75579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f544555c EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000040946400
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	a3 9a 87 8d 67 48 0f 	movabs %eax,0x3ab90f48678d879a
   7:	b9 3a
   9:	4c 8b 54 24 10       	mov    0x10(%rsp),%r10
   e:	4c 8b 4c 24 08       	mov    0x8(%rsp),%r9
  13:	44 8b 1c 24          	mov    (%rsp),%r11d
  17:	e9 05 f9 ff ff       	jmp    0xfffff921
  1c:	48 8d 3d 81 81 d0 0e 	lea    0xed08181(%rip),%rdi        # 0xed081a4
  23:	48 c7 c6 a3 9a 87 8d 	mov    $0xffffffff8d879aa3,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	4c 8b 54 24 10       	mov    0x10(%rsp),%r10
  34:	4c 8b 4c 24 08       	mov    0x8(%rsp),%r9
  39:	44 8b 1c 24          	mov    (%rsp),%r11d
  3d:	e9                   	.byte 0xe9
  3e:	1b f9                	sbb    %ecx,%edi