------------[ cut here ]------------
refcnt < 0
WARNING: net/bluetooth/hci_conn.c:567 at hci_conn_timeout+0xff/0x2c0, CPU#1: kworker/u11:0/23806
Modules linked in:
CPU: 1 UID: 0 PID: 23806 Comm: kworker/u11:0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci1 hci_conn_timeout
RIP: 0010:hci_conn_timeout+0xff/0x2c0
Code: 48 89 df e8 03 8a 09 00 eb 07 e8 bc 29 51 f7 b0 13 0f b6 f0 48 89 df 5b 41 5c 41 5e 41 5f 5d e9 57 b9 fe ff e8 a2 29 51 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:ffffc9002321fa50 EFLAGS: 00010293
RAX: ffffffff8a71704e RBX: ffff8881a5264000 RCX: ffff8881a7ecba80
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
RBP: 00000000ffffffff R08: ffff8881a5264013 R09: 1ffff11034a4c802
R10: dffffc0000000000 R11: ffffed1034a4c803 R12: dffffc0000000000
R13: ffff88816b427f18 R14: ffff8881a5264a40 R15: ffff8881a5264010
FS:  0000000000000000(0000) GS:ffff8882a9924000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2acb610ff8 CR3: 0000000181694000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 process_scheduled_works+0xaec/0x17a0
 worker_thread+0x89f/0xd90
 kthread+0x726/0x8b0
 ret_from_fork+0x51b/0xa40
 ret_from_fork_asm+0x1a/0x30
 </TASK>
