------------[ cut here ]------------
kernel BUG at fs/btrfs/volumes.c:890!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 16332 Comm: syz-executor.3 Not tainted 4.14.141 #37
kobject: 'kvm' (ffff8880a6e8d390): kobject_uevent_env
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a03f0700 task.stack: ffff888062db0000
RIP: 0010:btrfs_prepare_close_one_device fs/btrfs/volumes.c:890 [inline]
RIP: 0010:__btrfs_close_devices+0x7d8/0xa90 fs/btrfs/volumes.c:915
RSP: 0018:ffff888062db7700 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffff8880973f24c0 RCX: ffffc90008c4c000
RDX: 0000000000040000 RSI: ffffffff8265b718 RDI: 0000000000000286
kobject: 'kvm' (ffff8880a6e8d390): fill_kobj_path: path = '/devices/virtual/misc/kvm'
RBP: ffff888062db77c8 R08: ffff8880a03f0700 R09: ffff8880a03f0fc8
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888097ff1500
R13: ffff8880973f2588 R14: fffffffffffffff4 R15: dffffc0000000000
FS:  00007f66740e1700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000625208 CR3: 00000000a96ea000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kobject: 'loop0' (ffff8880a494f660): kobject_uevent_env
 btrfs_close_devices+0x29/0x140 fs/btrfs/volumes.c:948
 btrfs_mount+0x1fd9/0x2b28 fs/btrfs/super.c:1642
kobject: 'loop0' (ffff8880a494f660): fill_kobj_path: path = '/devices/virtual/block/loop0'
kobject: 'kvm' (ffff8880a6e8d390): kobject_uevent_env
 mount_fs+0x97/0x2a1 fs/super.c:1237
 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
kobject: 'kvm' (ffff8880a6e8d390): fill_kobj_path: path = '/devices/virtual/misc/kvm'
 vfs_kern_mount+0x40/0x60 fs/namespace.c:1036
 mount_subvol fs/btrfs/super.c:1392 [inline]
 btrfs_mount+0x3ce/0x2b28 fs/btrfs/super.c:1563
 mount_fs+0x97/0x2a1 fs/super.c:1237
 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x417/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c2ca
RSP: 002b:00007f66740e0a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
kobject: 'kvm' (ffff8880a6e8d390): kobject_uevent_env
RAX: ffffffffffffffda RBX: 00007f66740e0b40 RCX: 000000000045c2ca
RDX: 00007f66740e0ae0 RSI: 0000000020000100 RDI: 00007f66740e0b00
RBP: 0000000000000001 R08: 00007f66740e0b40 R09: 00007f66740e0ae0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004
R13: 00000000004c8980 R14: 00000000004df898 R15: 0000000000000003
Code: 
kobject: 'kvm' (ffff8880a6e8d390): fill_kobj_path: path = '/devices/virtual/misc/kvm'
c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 
kobject: 'loop0' (ffff8880a494f660): kobject_uevent_env
8e 59 02 00 00 48 8b 45 80 c7 80 10 01 00 00 00 00 00 00 e9 e2 f8 ff ff 
kobject: 'loop0' (ffff8880a494f660): fill_kobj_path: path = '/devices/virtual/block/loop0'
e8 58 2a f7 fe <0f> 0b e8 51 2a f7 
kobject: 'kvm' (ffff8880a6e8d390): kobject_uevent_env
fe 0f 0b 48 89 f7 e8 57 da 20 ff e9 ad 
kobject: 'kvm' (ffff8880a6e8d390): fill_kobj_path: path = '/devices/virtual/misc/kvm'
f8 ff 
RIP: btrfs_prepare_close_one_device fs/btrfs/volumes.c:890 [inline] RSP: ffff888062db7700
RIP: __btrfs_close_devices+0x7d8/0xa90 fs/btrfs/volumes.c:915 RSP: ffff888062db7700
---[ end trace 237d287a0ac75082 ]---
kobject: 'kvm' (ffff8880a6e8d390): kobject_uevent_env