loop0: detected capacity change from 0 to 32768
BTRFS: device fsid 14d642db-7b15-43e4-81e6-4b8fac6a25f8 devid 1 transid 8 /dev/loop0 (7:0) scanned by syz.0.0 (5335)
BTRFS info (device loop0): first mount of filesystem 14d642db-7b15-43e4-81e6-4b8fac6a25f8
BTRFS info (device loop0): using blake2b (blake2b-256-generic) checksum algorithm
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): using spread ssd allocation scheme
BTRFS info (device loop0): turning on async discard
BTRFS info (device loop0): enabling free space tree
BTRFS info (device loop0): use zlib compression, level 3
comedi comedi1: c6xdigio: I/O port conflict (0xf,3)
------------[ cut here ]------------
Unexpected driver unregister!
WARNING: drivers/base/driver.c:273 at 0x0, CPU#0: syz.0.0/5335
Modules linked in:
CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 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:driver_unregister+0x8d/0xa0 drivers/base/driver.c:273
Code: 73 68 4c 89 f7 e8 93 3e 9b fc 48 89 df 5b 41 5e 41 5f e9 e6 55 ff ff e8 31 34 f7 fb eb 05 e8 2a 34 f7 fb 48 8d 3d 63 0a c2 09 <67> 48 0f b9 3a 5b 41 5e 41 5f e9 44 70 81 05 cc cc cc cc 90 90 90
RSP: 0018:ffffc9000d407a20 EFLAGS: 00010283
RAX: ffffffff85c9da06 RBX: ffffffff8f1c9380 RCX: 0000000000100000
RDX: ffffc9000f612000 RSI: 00000000000008d4 RDI: ffffffff8f8be470
RBP: 0000000000000001 R08: ffff88803e1e012f R09: 1ffff11007c3c025
R10: dffffc0000000000 R11: ffffffff88b96490 R12: ffff88803e1e0038
R13: ffffffff8f1c92d0 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fe10acbf6c0(0000) GS:ffff88808d6b7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000010000 CR3: 0000000041d3d000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207
 comedi_device_detach drivers/comedi/drivers.c:215 [inline]
 comedi_device_attach+0x5d4/0x720 drivers/comedi/drivers.c:1011
 do_devconfig_ioctl drivers/comedi/comedi_fops.c:872 [inline]
 comedi_unlocked_ioctl+0x5ff/0x1020 drivers/comedi/comedi_fops.c:2178
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe109d8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe10acbf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe109fe5fa0 RCX: 00007fe109d8f7c9
RDX: 0000200000000300 RSI: 0000000040946400 RDI: 0000000000000007
RBP: 00007fe109e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe109fe6038 R14: 00007fe109fe5fa0 R15: 00007ffc023ecc58
 </TASK>
----------------
Code disassembly (best guess):
   0:	73 68                	jae    0x6a
   2:	4c 89 f7             	mov    %r14,%rdi
   5:	e8 93 3e 9b fc       	call   0xfc9b3e9d
   a:	48 89 df             	mov    %rbx,%rdi
   d:	5b                   	pop    %rbx
   e:	41 5e                	pop    %r14
  10:	41 5f                	pop    %r15
  12:	e9 e6 55 ff ff       	jmp    0xffff55fd
  17:	e8 31 34 f7 fb       	call   0xfbf7344d
  1c:	eb 05                	jmp    0x23
  1e:	e8 2a 34 f7 fb       	call   0xfbf7344d
  23:	48 8d 3d 63 0a c2 09 	lea    0x9c20a63(%rip),%rdi        # 0x9c20a8d
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	5b                   	pop    %rbx
  30:	41 5e                	pop    %r14
  32:	41 5f                	pop    %r15
  34:	e9 44 70 81 05       	jmp    0x581707d
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	cc                   	int3
  3c:	cc                   	int3
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop