------------[ cut here ]------------
refcnt < 0
WARNING: net/bluetooth/hci_conn.c:567 at hci_conn_timeout+0xff/0x2c0, CPU#1: kworker/u11:4/5623
Modules linked in:
CPU: 1 UID: 0 PID: 5623 Comm: kworker/u11:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci2 hci_conn_timeout
RIP: 0010:hci_conn_timeout+0xff/0x2c0
Code: 48 89 df e8 f3 b0 09 00 eb 07 e8 fc 64 28 f7 b0 13 0f b6 f0 48 89 df 5b 41 5c 41 5e 41 5f 5d e9 77 a8 fe ff e8 e2 64 28 f7 90 <0f> 0b 90 eb 8c 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 31 ff ff ff
RSP: 0018:ffffc90004507ab0 EFLAGS: 00010293
RAX: ffffffff8a9d3ece RBX: ffff8881b9b24000 RCX: ffff88810e4abb00
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
RBP: 00000000ffffffff R08: ffff8881b9b24013 R09: 1ffff11037364802
R10: dffffc0000000000 R11: ffffed1037364803 R12: dffffc0000000000
R13: ffff8881b9b24a40 R14: ffff8881b9b24a40 R15: ffff8881b9b24010
FS:  0000000000000000(0000) GS:ffff8882a9293000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c353611 CR3: 000000016b468000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
