Bluetooth: hci0: Opcode 0x0c1a failed: -4
Bluetooth: hci0: Error when powering off device on rfkill (-4)
============================================
WARNING: possible recursive locking detected
6.12.0-rc6-syzkaller-00192-gf1dce1f09380 #0 Not tainted
--------------------------------------------
syz.3.1682/11476 is trying to acquire lock:
ffff888024ea4078 (&hdev->lock){+.+.}-{3:3}, at: mgmt_set_connectable_complete+0x143/0x330 net/bluetooth/mgmt.c:1690

but task is already holding lock:
ffff888024ea4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x34c/0x1260 net/bluetooth/hci_sync.c:5193

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&hdev->lock);
  lock(&hdev->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz.3.1682/11476:
 #0: ffffffff8ff4a7c8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x168/0x570 net/rfkill/core.c:1293
 #1: ffff888024ea4d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:481
 #2: ffff888024ea4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x34c/0x1260 net/bluetooth/hci_sync.c:5193
 #3: ffff888024ea4690 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at: hci_cmd_sync_dequeue+0x50/0x1f0 net/bluetooth/hci_sync.c:887

stack backtrace:
CPU: 1 UID: 0 PID: 11476 Comm: syz.3.1682 Not tainted 6.12.0-rc6-syzkaller-00192-gf1dce1f09380 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_deadlock_bug+0x2e3/0x410 kernel/locking/lockdep.c:3037
 check_deadlock kernel/locking/lockdep.c:3089 [inline]
 validate_chain kernel/locking/lockdep.c:3891 [inline]
 __lock_acquire+0x2185/0x3ce0 kernel/locking/lockdep.c:5202
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
 mgmt_set_connectable_complete+0x143/0x330 net/bluetooth/mgmt.c:1690
 _hci_cmd_sync_cancel_entry.constprop.0+0x6c/0x1d0 net/bluetooth/hci_sync.c:645
 hci_cmd_sync_dequeue+0x178/0x1f0 net/bluetooth/hci_sync.c:890
 cmd_complete_rsp+0x46/0x1e0 net/bluetooth/mgmt.c:1461
 mgmt_pending_foreach+0xdf/0x140 net/bluetooth/mgmt_util.c:259
 __mgmt_power_off+0x12f/0x2c0 net/bluetooth/mgmt.c:9474
 hci_dev_close_sync+0xd37/0x1260 net/bluetooth/hci_sync.c:5201
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_rfkill_set_block+0x225/0x360 net/bluetooth/hci_core.c:911
 rfkill_set_block+0x203/0x560 net/rfkill/core.c:346
 rfkill_fop_write+0x2ce/0x570 net/rfkill/core.c:1301
 vfs_write+0x24c/0x1150 fs/read_write.c:681
 ksys_write+0x1fa/0x260 fs/read_write.c:736
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf739e579
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:00000000f568655c EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00000000200004c0
RDX: 0000000000000008 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), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi