------------[ cut here ]------------
refcnt < 0
WARNING: net/bluetooth/hci_conn.c:631 at hci_conn_timeout+0xff/0x2c0 net/bluetooth/hci_conn.c:631, CPU#1: kworker/u9:4/5632
Modules linked in:
CPU: 1 UID: 0 PID: 5632 Comm: kworker/u9:4 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: hci1 hci_conn_timeout
RIP: 0010:hci_conn_timeout+0xff/0x2c0 net/bluetooth/hci_conn.c:631
Code: 48 89 df e8 b3 c3 09 00 eb 07 e8 5c 4b 02 f7 b0 13 0f b6 f0 48 89 df 5b 41 5c 41 5e 41 5f 5d e9 57 a1 fe ff e8 42 4b 02 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:ffffc90004347ad0 EFLAGS: 00010293
RAX: ffffffff8ac4b8be RBX: ffff88807fc48000 RCX: ffff88807ef93e00
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
RBP: 00000000ffffffff R08: ffff88807fc48013 R09: 1ffff1100ff89002
R10: dffffc0000000000 R11: ffffed100ff89003 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88807fc48a40 R15: ffff88807fc48010
FS:  0000000000000000(0000) GS:ffff88812504e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f841883ca10 CR3: 00000000559de000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>