------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:593 at __mutex_lock_common kernel/locking/mutex.c:593 [inline], CPU#2: khidpd_10cf0000/9496
WARNING: kernel/locking/mutex.c:593 at __mutex_lock+0x93d/0x1b90 kernel/locking/mutex.c:776, CPU#2: khidpd_10cf0000/9496
Modules linked in:
CPU: 2 UID: 0 PID: 9496 Comm: khidpd_10cf0000 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:593 [inline]
RIP: 0010:__mutex_lock+0x944/0x1b90 kernel/locking/mutex.c:776
Code: c0 03 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 77 10 00 00 8b 35 7e db 41 05 85 f6 75 13 48 8d 3d 83 ed 44 05 48 c7 c6 c0 a9 8f 8b <67> 48 0f b9 3a 90 e9 20 f8 ff ff 31 c9 31 d2 48 89 df e8 a5 cd 6b
RSP: 0000:ffffc9000e757b00 EFLAGS: 00010246
RAX: 0000000000000003 RBX: ffff88805f444058 RCX: 1ffffffff216f456
RDX: 0000000000000000 RSI: ffffffff8b8fa9c0 RDI: ffffffff90bab4c0
RBP: ffffc9000e757c80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: ffffc9000e757cf8
FS:  0000000000000000(0000) GS:ffff8880975e3000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f7f3a190 CR3: 00000000648b1000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 l2cap_unregister_user+0x71/0x240 net/bluetooth/l2cap_core.c:1729
 hidp_session_thread+0x459/0x680 net/bluetooth/hidp/core.c:1304
 kthread+0x3b3/0x730 kernel/kthread.c:463
 ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
----------------
Code disassembly (best guess):
   0:	c0 03 0f             	rolb   $0xf,(%rbx)
   3:	b6 14                	mov    $0x14,%dh
   5:	11 38                	adc    %edi,(%rax)
   7:	d0 7c 08 84          	sarb   $1,-0x7c(%rax,%rcx,1)
   b:	d2 0f                	rorb   %cl,(%rdi)
   d:	85 77 10             	test   %esi,0x10(%rdi)
  10:	00 00                	add    %al,(%rax)
  12:	8b 35 7e db 41 05    	mov    0x541db7e(%rip),%esi        # 0x541db96
  18:	85 f6                	test   %esi,%esi
  1a:	75 13                	jne    0x2f
  1c:	48 8d 3d 83 ed 44 05 	lea    0x544ed83(%rip),%rdi        # 0x544eda6
  23:	48 c7 c6 c0 a9 8f 8b 	mov    $0xffffffff8b8fa9c0,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 20 f8 ff ff       	jmp    0xfffff855
  35:	31 c9                	xor    %ecx,%ecx
  37:	31 d2                	xor    %edx,%edx
  39:	48 89 df             	mov    %rbx,%rdi
  3c:	e8                   	.byte 0xe8
  3d:	a5                   	movsl  %ds:(%rsi),%es:(%rdi)
  3e:	cd 6b                	int    $0x6b