kobject: kobject_add_internal failed for hci0:0 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci0: failed to register connection device
------------[ cut here ]------------
refcnt < 0
WARNING: net/bluetooth/hci_conn.c:649 at hci_conn_timeout+0x16a/0x230 net/bluetooth/hci_conn.c:649, CPU#3: kworker/u34:1/5092
Modules linked in:
CPU: 3 UID: 0 PID: 5092 Comm: kworker/u34:1 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
Workqueue: hci0 hci_conn_timeout
RIP: 0010:hci_conn_timeout+0x16a/0x230 net/bluetooth/hci_conn.c:649
Code: 44 0f b6 2d fb fd 76 07 31 ff 41 83 e5 40 44 89 ee e8 5a 71 42 f7 45 84 ed 0f 84 02 ff ff ff e9 0d 49 a8 f6 e8 37 77 42 f7 90 <0f> 0b 90 e8 2e 77 42 f7 48 8d bb ed f5 ff ff 48 b8 00 00 00 00 00
RSP: 0018:ffffc90028f67bf8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888037954a50 RCX: 0000000000000000
RDX: ffff88802c534b00 RSI: ffffffff8ac9e039 RDI: ffff88802c534b00
RBP: 00000000ffffffff R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffff R11: 000000000000763b R12: ffff888037954000
R13: ffff88802c534fc4 R14: 0000000000000000 R15: ffff888036777c00
FS:  0000000000000000(0000) GS:ffff8880d4c46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557b5f5a28 CR3: 000000003d925000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>