------------[ cut here ]------------
WARNING: CPU: 0 PID: 6866 at fs/btrfs/volumes.c:1166 close_fs_devices+0x692/0x6f0 fs/btrfs/volumes.c:1166
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 6866 Comm: syz-executor.5 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d6/0x29e lib/dump_stack.c:118
 panic+0x2c0/0x800 kernel/panic.c:231
 __warn+0x227/0x250 kernel/panic.c:600
 report_bug+0x1b1/0x2e0 lib/bug.c:198
 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:close_fs_devices+0x692/0x6f0 fs/btrfs/volumes.c:1166
Code: 8a 04 28 84 c0 75 68 c6 03 00 48 83 c4 40 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 0a 6a 4e fe 0f 0b e9 7c ff ff ff e8 fe 69 4e fe <0f> 0b eb a8 89 d1 80 e1 07 80 c1 03 38 c1 0f 8c 9d f9 ff ff 48 89
RSP: 0018:ffffc90005637cc8 EFLAGS: 00010293
RAX: ffffffff8326a332 RBX: ffffffffffffffff RCX: ffff888052914040
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000000
RBP: ffff8880a4394108 R08: ffffffff8326a2d4 R09: ffffed1014872810
R10: ffffed1014872810 R11: 0000000000000000 R12: 1ffff11013f42a0a
R13: dffffc0000000000 R14: 1ffff11013f42a0c R15: ffff88809fa15060
 btrfs_close_devices+0x2f/0x130 fs/btrfs/volumes.c:1179
 close_ctree+0x5b2/0x6a3 fs/btrfs/disk-io.c:4149
 generic_shutdown_super+0x120/0x2a0 fs/super.c:464
 kill_anon_super+0x36/0x60 fs/super.c:1108
 btrfs_kill_super+0x3d/0x50 fs/btrfs/super.c:2265
 deactivate_locked_super+0xa7/0xf0 fs/super.c:335
 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1118
 task_work_run+0x137/0x1c0 kernel/task_work.c:141
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:165 [inline]
 exit_to_user_mode_prepare+0x11a/0x1e0 kernel/entry/common.c:192
 syscall_exit_to_user_mode+0x82/0x1d0 kernel/entry/common.c:267
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x460027
Code: 64 89 04 25 d0 02 00 00 58 5f ff d0 48 89 c7 e8 2f be ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 fd 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe4600c5a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000460027
RDX: 0000000000403188 RSI: 0000000000000002 RDI: 00007ffe4600c650
RBP: 00000000000002ca R08: 0000000000000000 R09: 000000000000000b
R10: 0000000000000005 R11: 0000000000000246 R12: 00007ffe4600d6e0
R13: 0000000003115a60 R14: 0000000000000000 R15: 00007ffe4600d6e0
Kernel Offset: disabled
Rebooting in 86400 seconds..