------------[ cut here ]------------
WARNING: CPU: 1 PID: 8663 at fs/btrfs/volumes.c:1168 close_fs_devices+0x772/0x9a0 fs/btrfs/volumes.c:1168
Modules linked in:
CPU: 0 PID: 8663 Comm: syz-executor.5 Not tainted 5.13.0-rc2-next-20210518-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:close_fs_devices+0x772/0x9a0 fs/btrfs/volumes.c:1168
Code: e8 53 af 32 fe 85 db 0f 85 07 f9 ff ff e8 06 a8 32 fe 0f 0b e9 fb f8 ff ff e8 fa a7 32 fe 0f 0b e9 e2 fd ff ff e8 ee a7 32 fe <0f> 0b e9 19 fe ff ff 48 c7 c7 6c f7 e9 8d e8 fb 09 78 fe e9 bb f8
RSP: 0018:ffffc900018cfbd0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff888018cfd580 RSI: ffffffff83432be2 RDI: 0000000000000003
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffff888029c1c93b
R10: ffffffff834329f9 R11: 0000000000000000 R12: ffff888029c1c938
R13: 0000000000000000 R14: ffff88802a330d08 R15: ffff888029c1c850
FS:  0000000002c24400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005580c4875d38 CR3: 000000007c3d5000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 btrfs_close_devices+0x8e/0x4b0 fs/btrfs/volumes.c:1180
 close_ctree+0x752/0x795 fs/btrfs/disk-io.c:4438
 generic_shutdown_super+0x14c/0x370 fs/super.c:465
 kill_anon_super+0x36/0x60 fs/super.c:1057
 btrfs_kill_super+0x38/0x50 fs/btrfs/super.c:2379
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 deactivate_super+0xad/0xd0 fs/super.c:366
 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1136
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x26f/0x280 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
 do_syscall_64+0x3e/0xb0 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467a37
Code: ff d0 48 89 c7 b8 3c 00 00 00 0f 05 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd2f8e1098 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a37
RDX: 00007ffd2f8e116b RSI: 0000000000000002 RDI: 00007ffd2f8e1160
RBP: 00007ffd2f8e1160 R08: 00000000ffffffff R09: 00007ffd2f8e0f30
R10: 0000000002c258e3 R11: 0000000000000246 R12: 00000000004bee70
R13: 00007ffd2f8e2230 R14: 0000000002c25810 R15: 00007ffd2f8e2270