Bluetooth: hci0: command 0x0419 tx timeout
------------[ cut here ]------------
refcnt < 0
WARNING: net/bluetooth/hci_conn.c:567 at hci_conn_timeout+0x16a/0x230 net/bluetooth/hci_conn.c:567, CPU#3: kworker/u33:4/5938
Modules linked in:
CPU: 3 UID: 0 PID: 5938 Comm: kworker/u33:4 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: hci0 hci_conn_timeout
RIP: 0010:hci_conn_timeout+0x16a/0x230 net/bluetooth/hci_conn.c:567
Code: 44 0f b6 2d 1b 4a 3e 06 31 ff 41 83 e5 40 44 89 ee e8 fa 9e 91 f7 45 84 ed 0f 84 02 ff ff ff e9 dc 23 fc f6 e8 97 a4 91 f7 90 <0f> 0b 90 e8 8e a4 91 f7 48 8d bb fd f5 ff ff 48 b8 00 00 00 00 00
RSP: 0018:ffffc90003dafc20 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888034a64a40 RCX: ffffffff8a7573ef
RDX: ffff888023540000 RSI: ffffffff8a7574e9 RDI: ffff888023540000
RBP: 00000000ffffffff R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffff R11: 00000000000075e9 R12: ffff888034a64000
R13: ffff888023540484 R14: 0000000000000000 R15: ffff88810680fc00
FS:  0000000000000000(0000) GS:ffff8880d68b9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3914db CR3: 0000000058b60000 CR4: 0000000000352ef0
DR0: 0000000000000006 DR1: 0000000000000002 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
 kthread+0x370/0x450 kernel/kthread.c:467
 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>